Codigo de Fallas Payloader PAYLOADER 966G

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Producto: WHEEL LOADER

Modelo: 966F II WHEEL LOADER 1SL01330

Configuracin: 966F Series II Wheel Loader 1SL00507-UP (MACHINE) POWERED BY 3306 Engine

Pruebas y AjustesCOMPUTERIZED MONITORING SYSTEM (CMS) WITH VFD CIRCULAR GAUGE

Nmero de medio -SENR5247-03 Fecha de publicacin -29/12/1995 Fecha de actualizacin -11/10/2001

Testing And Adjusting

Introduction

Reference: For machine specific operation information, see the Operation And Maintenance Manual

for the machine being serviced.

Reference: For machine specific electrical circuit information, see the Electrical System Schematic

module for the machine being serviced.

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The troubleshooting of the CMS system requires additional information from the machine Service

Manual. The Electrical System Schematic and the Operation & Maintenance Manual are required

support material.

As a guide, a Typical CMS Schematic is at the end of this manual. For an accurate representation of

the machine being diagnosed, see the Electrical System Schematic in the machine Service Manual.

When the troubleshooting procedure instructs to REPAIR THE HARNESS, use the Electrical System

Schematic in the machine Service Manual to trace the circuit. Perform continuity checks at connectors

to locate harness failures. At component connectors, always check the ground circuit. Less than five

ohms of resistance is required between the connector ground contacts and frame ground. Excessive

ground resistance, greater than five ohms, can cause incorrect diagnosing of problems.

During troubleshooting, inspect all component and harness connections before any component is

replaced. If these connections are not clean and tight they can cause electrical problems, either



permanent or intermittent (come and go). Make sure the connections are tight before other tests are

made.

Failure of an electrical component can cause, or be caused by the failure of one or more other

components. Always attempt to find and correct the cause of electrical system failure before making

replacement of a component.

Harness Connector Inspection

Intermittent electrical problems are often caused by poor connections at harness connectors. Use the

following checks as a guide for inspecting connectors.

CHECK Connector Mating:

* Ensure locking rings lock into place.

* Ensure that locking clips are used on Sure Seal connectors.

* Ensure that the screw is tight in the center of DRC connectors.

* Ensure that the connector contacts (pins and sockets) align properly.

CHECK Wires At The Connector:

* Ensure that the wires enter the back of the connector straight not at an angle.

* Ensure that each wire is properly crimped into the proper connector contact.

* Ensure that each connector contact is properly locked into the connector body. When locked

properly, the contact (or wire) cannot be pulled out of the connector body without excessive

force.

CHECK Each Wire For Nicks Or Signs Of Abrasion In The Insulation.

CHECK For Dirty Or Corroded Contacts (Pins And Sockets):

Clean contacts (pins and sockets) with a cotton swab or a soft brush and denatured alcohol only.

CHECK For Moisture At The Connector. Possible Sources Are:

* Damaged or lost connector seals.

* Missing or loose wire hole plugs.

* Wires not entering the back of the connector straight. If wires enter at an angle, there may not

be a good seal between the connector and the wire insulation.

* Other connectors with poor seals may allow moisture to travel inside the wire insulation.

CHECK The Fit Of Each Contact (Pin And Socket):

Insert a new pin or socket into each contact of the connector. It should fit snugly. The new pin or

socket should stay in place if the connector is held with the contacts facing down.

CMS Service Connector



Connectors (966F Shown)

(1) Harness code connector. (2) Units connector. (3) Service connector. (4) CAT data link connector.

Service connector (3) provides access to the service and clear inputs. Connector contact 1 is the

service input and contact 2 is the clear input. Service connector (3) is usually located under the dash

within the operator compartment. The service connector is a Sure-Seal or DT type of connector. For

a more accurate service connector location and connector requirements, see the Electrical System

Schematic in the machine Service Manual.

Service Connector With Jumpers - Typical Example Connector end view shows Sure Seal and DT types of connector.

(3) Service connector. (5) Jumper - service contact grounded. (6) Jumper - clear contact grounded.

Various diagnostic functions require the grounding and/or opening of the service and clear contacts at

the service connector. During troubleshooting, it is necessary for the service person to make the

proper electrical connections between the contacts of the service connector. These electrical

connections are made with two jumpers. Also see the topic Service Tools.

Service Tools

The following service tools should be used to make troubleshooting the electrical system easier.



6V-7070 or 9U-7330 or equivalent Digital Multimeter.8T-3224 Needle Tip Group.7X-1710 Cable

Probe Group.8T-8726 Adapter Cable6V-3000 Repair Kit - Sure Seal4C-3406 Connector Repair Kit -

Deutsch

Use the digital multimeter for making continuity (resistance) checks or voltage measurements. For

instruction on use of the 6V-7070, see Special Instruction SEHS7734. The 7X-1710 Cable Probe

Group is used to make measurements at connectors without disconnecting them. The probes are

pushed in the back of the connector alongside the wire. The 8T-8726 Adapter Cable is a 3 pin

breakout cable used to make measurements in sensor circuits.

NOTE: Use of continuity testers (such as 8T-0500), or voltage testers (such as 5P-7277) are not

recommended for use on present-day Caterpillar electrical circuits, except for harness tests.

4C-8195 Control Service Tool



The 4C-8195 Control Service Tool is helpful for the service person to make the proper electrical

connections at the service connector during troubleshooting. Three connectors are wired in parallel so

that the service tool is usable on the different types of machine harnesses.

Actuating the mode switch scrolls through the display modes. Actuating the scroll switch scrolls the

display with the control in the service or numeric readout mode. Actuating the clear switch when in

service mode, clears the fault being continuously shown. Actuating the clear switch when in tattle tale

mode, clears all extreme values.

Diagnostic Summary



The following topics summarize the diagnostics of CMS. See the Systems Operation section of this

Service Manual for a detailed explanation of the topics.

Changing Modes

Digital Readout Area

(1) Mode readout.

CMS has five modes of operation. The different modes are identified by the mode number which is

shown on mode readout (1). The five modes of operation and the corresponding mode numbers are:

Normal Mode - "-0-" is shown on mode readout (1).

Service Mode - "-1-" is shown on mode readout (1).

Status Mode - "-2-" is shown on mode readout (1).

Tattletale Mode - "-3-" is shown on mode readout (1).

Numeric Readout Mode - "-4-" is shown on mode readout (1).

CMS enters normal mode when power is applied. The mode of operation is changeable at any time.

Grounding the service and clear contacts of the service connector at the same time initiates the

scrolling of the mode numbers on mode readout (1). Removing ground from both connector contacts,

causes the CMS control to enter the mode which is currently shown.

Procedure

1. Turn key start switch ON. Wait for the Self Test to finish; approximately seven seconds.

2. At the same time, ground the service and clear contacts of the service connector. This causes the

mode numbers ("-0-" through "-4-") to scroll on mode readout (1).



3. When the desired mode number is shown on mode readout (1), remove ground from (open) the

service and clear contacts. The desired mode is now entered and active.

Service Mode (Mode 1)

Service Mode Display

(1) Module identifier (MID). (2) Failure mode identifier (FMI). (3) Component identifier (CID). (4) Fault present

indicator. (5) Status change identifier. (6) CMS contact identifier.

Service mode diagnoses detected faults in the output circuits and sensor input circuits. The

information available from service mode is:

* MID (1) shows which electronic machine system detected and diagnosed the fault. Some

MID's are:

CMS ... 26

Electronic Transmission Control ... 27

Autoshift Transmission Control ... 81

All the MID's for the electronic controls that "talk" to CMS on a particular machine are listed

on the Electrical System Schematic.

* CID (3) shows which component is faulty. For a list of CID codes for CMS, see the CMS

Detected Faults chart in the Detected Faults section.

* FMI (2) shows what type of failure has occurred. For a list of FMI codes that CMS uses, see

the CMS Detected Faults chart in the Detected Faults section.

* Fault present indicator (4) shows the status of the fault shown. If fault present indicator (4)

shows "SERV CODE", then the fault is currently present. If fault present indicator (4) is OFF,

then the fault was present in the past but is not present now (intermittent).

* The action alarm SOUNDS when the fault shown changes status (present or not present).



* CMS contact identifier (6) shows the CMS connector contact for the fault currently shown.

* Status change identifier (5) shows the CMS connector contact for any faults that change status

(present or not present).

There are three display operations while in service mode: scrolling faults, holding faults and clearing

faults. When service mode is first entered the fault shown is on-hold.

* To scroll through all faults, ground the service contact of the service connector.

* To hold a fault, open (remove ground from) the service contact of the service connector while

the desired fault is shown.

* To clear a fault, ground the clear contact of the service connector while the fault is on-hold. A

fault that is currently present (fault present indicator shows "SERV CODE") can not be cleared.

For a detailed explanation, see the topic Service Mode (Mode 1) in the Systems Operation section.

Status Mode (Mode 2)



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Status Mode Display

(1) Status change identifier. (2) Open contact identifier. (3) Alert indicators with assigned numbers.

There are two versions of status mode, one version for earlier CMS controls and one version for later

CMS controls. Status mode on earlier CMS controls, uses both the alert indicators and the open

contact identifier to show the status of the switch inputs. Status mode on later CMS controls, uses

only the open contact identifier to show the status of the switch inputs; the alert indicators are not

used. Earlier CMS controls are Part Numbers: 9X9887 and 101-3371. All other CMS part numbers

are later CMS controls.

Status mode diagnostics assist with troubleshooting of faults in the switch input circuits. The

information available from status mode is:

* The action alarm SOUNDS when any switch input changes status (open or ground).

* Status change identifier (1) shows the CMS connector contact for any switch inputs that

change status (open or ground).

* Open contact identifier (2) shows the CMS connector contact for any switch inputs that are

open. On earlier CMS controls, the alert indicator which is ON CONTINUOUSLY corresponds

to the connector contacts that are now shown.

* On earlier CMS controls, alert indicators (3) show the status (open or grounded) of switch

inputs. If alert indicator (3) is OFF, then the corresponding switch type input is grounded. If

alert indicator (3) is FLASHING, then the corresponding switch type input is open. If alert

indicator (3) is ON CONTINUOUSLY, then the corresponding switch type input is open and

the CMS connector contact is now shown at open contact identifier (2).

On earlier CMS controls, selection is the only display operation of status mode. Which group of CMS

connector contacts are shown on the CMS display is determined by the status of the clear contact of

the service connector.

* To select CMS connector contacts 19, 30 - 40; open the clear contact of the service connector.



* To select CMS connector contacts 5, 6, 20, 21, 22, 25 - 29; ground the clear contact of the

service connector.

For a detailed explanation of status mode, see the topic Status Mode (Mode 2) in the Systems

Operation section.

Tattletale Mode (Mode 3)

Tattletale mode diagnostics show the extreme value for each machine condition monitored. The

values are shown and read in the same manner as when in normal mode. Clearing is the only display

operation of tattletale mode. To clear all the extreme values; ground the clear contact of the service

connector. For a detailed explanation, see the topic Tattletale Mode (Mode 3) in the Systems

Operation section.

Numeric Readout Mode (Mode 4)

Numeric readout mode diagnostics show a numeric value of the information from each sensor input.

(Sensor input information is that which is shown on the gauges and the speed readout.) The numeric

value shown is constantly updated to reflect any changes that occur.

Scrolling and holding are the display operations of numeric readout mode.

* To hold the desired information, open the service contact of the service connector.

* To scroll all the information, ground the service contact of the service connector.

NOTE: For the earliest CMS controls, activation of scrolling and holding is the opposite of what is

described above. To scroll, open the service contact. To hold, ground the service contact.

For a detailed explanation, see the topic Numeric Readout Mode (Mode 4) in the Systems Operation

section.

Detected Faults



When the CMS control detects a fault while in normal mode, the service code indicator shows "SERV

CODE"; which notifies the service person. Service mode shows the diagnostics for the detected fault.

For detailed information, see the topic Service Mode (Mode 1) in the Systems Operation section.

NOTE: When a sensor fault is present, the corresponding warning for the operator is also activated.

For example, if the signal wire for the engine coolant temperature sensor is shorted to +battery, then:

a. SERV CODE indicator is ON.

b. The corresponding service code is stored in memory.

c. The gauge for engine coolant temperature shows in the problem region.

d. The action lamp is FLASHING.



Notice that the above items c and d are the same warning indications that are activated if the engine

were to actually overheat.

NOTE: This Service Manual applies only to CMS faults. When in service mode (on appropriately

equipped machines), faults from electronic control modules other than the CMS control are shown.

The CAT data link facilitates the transfer of diagnostic information from other electronic control

modules to the CMS control. This diagnostic information is shown when CMS is in service mode.

The module identifier (MID) tells which electronic control module is diagnosing the detected fault.

The MID code for CMS is "26". This Service Manual applies only to faults with a MID of "26" (CMS

faults). The MID code of other electronic control modules (transmission, engine) on a particular

machine are listed on the Electrical System Schematic.

Initial Troubleshooting Procedure

Digital Readout Area

(1) Module identifier (MID). (2) Failure mode identifier (FMI). (3) Component identifier (CID). (4) Fault present

indicator. (5) Status change identifier. (6) CMS contact identifier.

Use the following procedure when a fault is detected. When a fault is detected, the service code

indicator shows "SERV CODE" while in normal mode.

1. Enter service mode (mode 1).

2. A single fault is shown and is on-hold at this time. When no fault is available; MID (1) shows "--",

CID (3) shows "---" and FMI (2) shows "-F".

3. To see all detected faults, scroll the faults. To do so, ground the service contact of the service

connector.

4. Place the desired fault on-hold (stop the scrolling). To do so, remove ground from the service

contact of the service connector when the desired fault is shown.



5. Make sure that MID (1) is "26". If not, see the topic Service Mode (Mode 1).

6. Observe fault present indicator (4):

* If fault present indicator (4) shows "SERV CODE", then the fault shown is currently present.

* If fault present indicator (4) is OFF, then the fault shown is not present at this time. The fault

has occurred and then went away, sometime in the past (intermittent).

7. To troubleshoot the fault, go to the procedure with the same CID and FMI.

8. After a fault is corrected or it is no longer needed, clear the fault. To do so, momentarily ground the

clear contact of the service connector while the fault is on-hold. After clearing, the display advances

to the next available fault.

9. Repeat Steps 2 through 8 for the remaining faults. Return to normal mode when finished.

Troubleshooting Procedures:

Go to the procedure which corresponds to the CID and FMI shown on the CMS display in the digital

readout area.

CID 096 Procedure (Fuel Level Sensor), CID 100 Procedure (Engine Oil Pressure

Sensor), CID 110 Procedure (Engine Coolant Temp Sensor), CID 177 Procedure

(Power Train Oil Temp Sensor), CID 427 Procedure (Front Brake Oil Temp

Sensor), CID 428 Procedure (Rear Brake Oil Temp Sensor), CID 600 Procedure

(Hydraulic Oil Temp Sensor), CID 601 Procedure (Brake Air Pressure Sensor)

Service Notes: Ensure that the desired fault (CID and FMI) is on-hold. Ensure that the fault present

indicator shows "SERV CODE". Make a note of the connector contact shown on the CMS contact

identifier. This is the signal contact of the CMS connector which corresponds to the currently shown

CID.

NOTE: The Sensor Voltage Test within the topic PWM Sensor Tests also covers the troubleshooting

of the sensor fault.

FMI 0F

This fault is recorded when the CMS control reads the sensor signal as too high. The result of this

fault condition is that the corresponding gauge FLASHES. The possible causes are:

* Sensor is defective.

* Sensor ground circuit in the machine harness is open.

* Signal circuit in the machine harness is shorted to +battery.

* Signal circuit in the machine harness is open (a disconnected sensor is included).

* CMS control is defective.



1. CHECK CONTROL AND HARNESS - Turn the disconnect and key start switches to the ON

position. Disconnect the machine harness from the sensor. At the machine harness connector for the

sensor, measure the voltage (DCV) between the signal contact and the ground contact.

* Voltage is 5.0 0.5 DCV; CMS control and harness are correct. The sensor is defective.

Replace the sensor, also see the topic PWM Sensor Tests.

* Voltage is NOT 5.0 0.5 DCV; CMS control or harness are defective. Go to Step 2.

2. CHECK HARNESS GROUND CIRCUIT - The sensor remains disconnected. Turn the disconnect

and key start switches to the OFF position. Disconnect the machine harness from the CMS control. At

the machine harness connector for the sensor, measure the resistance between the ground contact and

frame ground.

* Resistance is greater than 2.0 Ohms; the ground circuit in the harness is defective. There is an

open circuit between the ground contact and frame ground. Repair or replace the machine

harness.

* Resistance is less than 2.0 Ohms; harness resistance is correct. Go to Step 3.

3. CHECK FOR SHORTED HARNESS - The sensor and CMS control remain disconnected from the

machine harness. The disconnect switch remains OFF. At the machine harness connector for the

sensor, measure the resistance between the signal contact and the +battery contact (+V).

* Resistance is less than 5000 Ohms; the machine harness is defective. There is a short between

the +battery circuit and the signal circuit in the machine harness. Repair or replace the machine

harness.

* Resistance is greater than 5000 Ohms; harness circuit resistance is correct. Go to Step 4.

4. CHECK FOR OPEN HARNESS - The sensor and CMS control remain disconnected from the

machine harness. The disconnect switch remains OFF. Check the continuity of the signal circuit from

the CMS machine harness connector to the sensor machine harness connector.

* Resistance is less than 5 Ohms; the signal circuit is correct. The CMS control is defective.

Replace the CMS control; see CMS Control Replacement.

* Resistance is greater than 5 Ohms; the signal circuit is defective. The signal circuit is open in

the machine harness. Repair or replace the machine harness.

FMI 1F

This fault is recorded when the CMS control reads the sensor signal as too low. The result of this fault

condition is that the corresponding gauge FLASHES. The possible causes are:

* Sensor is defective.

* Signal circuit in the machine harness is shorted to ground.

* CMS control is defective.

NOTE: Step 1 can create an FMI OF fault for the same CID No. When all harnesses are reconnected,

this fault is shown as not present. Clear the FMI OF fault after this procedure is completed.



1. CHECK SENSOR - Ensure that the desired fault (CID) is on-hold and that the fault present

indicator shows "SERV CODE". Observe the status of the fault present indicator or listen for the

SOUNDING of the action alarm. Disconnect the machine harness from the sensor.

* "SERV CODE" is NO longer shown or the action alarm SOUNDED; indicates the fault is no

longer present. The sensor is defective. Replace the sensor, also see the topic PWM Sensor

Tests.

* "SERV CODE" remains shown or the action alarm did NOT SOUND; indicates the fault

remains present. The sensor is not causing the fault. Go to Step 2.

2. CHECK FOR SHORT TO GROUND - The sensor remains disconnected from the machine

harness. Turn the disconnect switch to the OFF position. Disconnect the machine harness from the

CMS control. At the machine harness connector for the CMS control, measure the resistance between

the signal contact and frame ground.

* Resistance is greater than 5000 Ohms; harness circuit resistance is correct. The control is

defective. Replace the CMS control; see CMS Control Replacement.


frame ground and the signal circuit in the machine harness. Repair or replace the machine

harness.

CID 168 Procedure (Electrical System Voltage)

Service Notes: Ensure that the fault present indicator shows "SERV CODE".

FMI 3F

This fault is recorded when the CMS control reads the electrical system voltage as above normal. The

result of this fault condition is that the system voltage gauge FLASHES if the machine is so equipped.

CHECK SYSTEM VOLTAGE - Run the engine at high idle. Measure the system voltage (+battery)

at the alternator circuit breaker or at the batteries.

* Voltage is greater or equal to 36.0 DCV; the charging system is defective. A possible cause is

a faulty alternator with excessive current output and therefore high voltage. Repair the charging

system. See the topic Electrical System Tests in the Testing And Adjusting section of this

Service Manual.

* Voltage is less than 36.0 DCV; the charging system voltage is less than the required amount

to cause this fault. The CMS control is defective. Replace the CMS control; see CMS Control

Replacement.

CID 248 Procedure (CAT Data Link)

Service Notes: Ensure that the fault present indicator shows "SERV CODE".

FMI 9F

This fault is recorded when the CMS control does not receive expected information. For example;

engine oil pressure or actual gear information is not received from other electronic control modules



through the CAT data link. The result of this fault condition is that the gauges dependent upon the

CAT data link FLASH. The possible causes (listed in order of probability) are:

1. Poor electrical connection at a machine harness connector.

2. CAT data link circuit in the machine harness is shorted to ground.

3. CAT data link circuit in the machine harness is shorted to +battery.

4. CAT data link circuit in the machine harness is open.

5. An electronic control module which uses CAT data link is defective (CMS control, engine

control, transmission control, etc.)

NOTE: If the CMS control was recently replaced, see the topic Initialization.

1. Check other electronic control modules for a similar fault. If a similar fault is found, use the

procedures for that electronic control module to troubleshoot the fault. Otherwise, go to Step 2.

2. INSPECT HARNESS CONNECTORS - Turn the disconnect to the OFF position. Inspect the

machine harness connections related to the CAT data link. Make sure that connectors are clean and

tight. If necessary, repair or replace the machine harness. Otherwise, go to Step 3.

3. CHECK FOR SHORT TO GROUND - The disconnect switch remains OFF. Disconnect the

machine harness from all electronic control modules that use the CAT data link. At the machine

harness connector for the CMS control, measure the resistance between frame ground and the CAT

data link circuits (CMS connector contacts 23 and 24).


frame ground and the CAT data link circuit in the machine harness. Repair or replace the

machine harness.


4. CHECK FOR SHORT TO +BATTERY - The disconnect switch remains OFF. All related control

modules remain disconnected from the machine harness. At the machine harness connector for the

CMS control, measure the resistance between +battery (contact 1) and the CAT data link circuits

(CMS connector contacts 23 and 24).


+battery and the CAT data link circuit in the machine harness. Repair or replace the machine

harness.


5. CHECK FOR OPEN HARNESS - The disconnect switch remains OFF. All related control modules

remain disconnected from the machine harness. Check the continuity of the CAT data link circuit in

the machine harness. Measure from the CMS control connector (contacts 23 and 24) to the connector

for each of the related electronic control modules.

* Resistance is greater than 5 Ohms; the machine harness is defective. The CAT data link

circuit is open in the machine harness. Repair or replace the machine harness.

* Resistance is less than 5 Ohms; the CAT data link circuit in the machine harness is correct.

The CMS control is defective. Replace the CMS control; see CMS Control Replacement.

CID 270 Procedure (CMS Harness Code)



Service Notes: The connector contacts, which correspond to CID 270, are not shown on the CMS

contact identifier. The fault is present in any of the five harness code contacts. Ensure that the fault

present indicator shows "SERV CODE".

NOTE: To troubleshoot an intermittent CID 270 fault, see the topic Harness Code Fault in the

Undetected Faults section.

FMI 2F

This fault is recorded when the harness code circuits change during normal operation. If this fault is

present when CMS is turned ON, the control does not function correctly. This is easily noticed

because the self test does not function and only the CAT logo is shown in the digital readout area.

1. Perform the self test, see Self Test.

* Passes the self test and fault CID 270 remains present; the control is defective. Replace the

CMS control; see CMS Control Replacement.

* Fails the self test; there is a defect. More troubleshooting is required; see the topic Harness

Code Fault in the Undetected Fault section.

CID 271 Procedure (Action Alarm)

Service Notes: Ensure that fault CID 271 and the desired FMI are on-hold. Ensure that the fault

present indicator shows "SERV CODE". Make a note of the connector contact shown on the CMS

contact identifier. This is the contact of the CMS connector which corresponds to fault CID 271.

FMI 3F

This fault is recorded when the CMS control reads the voltage of the action alarm circuit (410-WH) as

above normal (shorted to +battery). The result of this fault condition is that the action alarm SOUNDS

CONTINUOUSLY.

CHECK ALARM CIRCUIT - Turn the disconnect and the key start switches to the OFF position.

Disconnect the machine harness from the CMS control. Turn the disconnect switch to the ON

position. Listen for the SOUNDING of the action alarm. Turn the key start switch to the ON position.

* The alarm SOUNDS; harness circuit 410-WH is shorted to +battery. Repair or replace the

harness.

* The alarm does NOT SOUND; the control is defective. Replace the CMS control; see CMS

Control Replacement.

FMI 4F

This fault is recorded when the CMS control reads the voltage of the action alarm circuit (410-WH) as

below normal (shorted to ground). The result of this fault condition is that the action alarm does not

SOUND.

NOTE: This procedure can create a CID 271 FMI 5F fault. When all harnesses are reconnected, this

fault is shown as not present. Clear the CID 271 FMI 5F fault after this procedure is completed.



1. CHECK ALARM - Ensure that CID 271 FMI 4F is on-hold and that the fault present indicator

shows "SERV CODE". Observe the status of the fault present indicator. Disconnect the machine

harness from the alarm.

* "SERV CODE" is NO longer shown; the alarm is defective. Replace the action alarm. (Note:

The correct resistance for a good alarm is 200 100 Ohms.)

* "SERV CODE" remains shown; indicates the fault remains present. The action alarm is not

causing the fault. Go to Step 2.

2. CHECK FOR SHORT TO GROUND - Turn the disconnect switch to the OFF position. The alarm

remains disconnected from the machine harness. Disconnect the machine harness from the CMS

control. At the machine harness connector for the CMS control, measure the resistance between

contact 3 (410-WH) and frame ground.

* Resistance is less than 5000 Ohms; harness is defective. Repair or replace the machine

harness.

* Resistance is greater than 5000 Ohms; harness resistance is correct. Go to Step 3.

3. CHECK CONTROL - Remove contact 3 from the machine harness connector for the CMS control.

Reconnect the harness connector to the CMS control. Turn the disconnect switch to the ON position.

Put the system in service mode with CID 271 FMI 4F on-hold. Observe the fault present indicator.

* "SERV CODE" is shown; indicates the control thinks the fault is present. The control is


* "SERV CODE" is NOT shown; indicates the fault is no longer present. The control is not

causing the fault. The fault is intermittent. The probable cause is poor electrical connection at

the harness connectors or a damaged harness. Check the harness for damage and clean the

harness connectors.

FMI 5F

This fault is recorded when the CMS control reads the current of the action alarm circuit (410-WH) as

below normal (open circuit). The result of this fault condition is that the action alarm does not

SOUND.



1. CHECK ALARM - Ensure that CID 271 FMI 5F is on-hold and that the fault present indicator

shows "SERV CODE". Observe the status of the fault present indicator. Disconnect the machine

harness from the alarm. At the machine harness connector for the alarm, place a jumper across the

two contacts.

* "SERV CODE" is NO longer shown; the alarm is open. Replace the action alarm. (Note: The

correct resistance for a good alarm is 200 100 Ohms.)

* "SERV CODE" remains shown; indicates the fault remains present. The action alarm is not

causing the fault. Go to Step 2.

2. CHECK HARNESS - Turn the disconnect switch to the OFF position. From Step 1; remove the

jumper and reconnect the alarm to the machine harness. Disconnect the machine harness from the



CMS control. At the machine harness connector for the CMS control, measure the resistance between

contact 3 (410-WH) and frame ground.

* Resistance is greater than 300 Ohms; harness circuit is open. Go to Step 3.

* Resistance is less than 300 Ohms; harness circuit resistance is correct. Go to Step 4.

3. CHECK HARNESS - Disconnect the machine harness from the alarm. Check for an open in circuit

410-WH between CMS machine harness connector (contact 3) and action alarm machine harness

connector (contact 1). Also, check for an open in circuit 201-BK between action alarm machine

harness connector (contact 2) and frame ground. Repair or replace the harness.

4. CHECK CONTROL - Reconnect the harness connector to the CMS control. Reconnect the alarm

to the machine harness. Turn the disconnect switch to the ON position. Put the system in service

mode with CID 271 FMI 5F on-hold. Observe the fault present indicator.






harness connectors.

CID 324 Procedure (Action Lamp)

Service Notes: Ensure that fault CID 324 and the desired FMI are on-hold. Ensure that the fault

present indicator shows "SERV CODE". Make a note of the connector contact shown on the CMS

contact identifier. This is the contact of the CMS connector which corresponds to fault CID 324.

FMI 3F

This fault is recorded when the CMS control reads the voltage of the action lamp circuit (411-PK) as

above normal (shorted to +battery). The result of this fault condition is that the action lamp is ON

CONTINUOUSLY.

CHECK LAMP CIRCUIT - Turn the disconnect and the key start switches to the OFF position.

Disconnect the machine harness from the CMS control. Turn the disconnect switch to the ON

position. Observe the action lamp. Turn the key start switch to the ON position.

* The lamp is ON; harness circuit 411-PK is shorted to +battery. Repair or replace the harness.

* The lamp is OFF; the control is defective. Replace the CMS control; see CMS Control

Replacement.

FMI 4F

This fault is recorded when the CMS control reads the voltage of the action lamp circuit (411-PK) as

below normal (shorted to ground). The result of this fault condition is that the action lamp does not

light.





1. CHECK LAMP - Ensure that CID 324 FMI 4F is on-hold and that the fault present indicator shows

"SERV CODE". Observe the status of the fault present indicator or listen for the SOUNDING of the

action alarm. At the action lamp, disconnect wire 411-PK from the action lamp socket.

* "SERV CODE" is NO longer shown or the action alarm SOUNDED; the lamp is defective.

Replace the action lamp. (Note: For the purposes of this procedure, the correct resistance for a

lamp is greater than 2 Ohms.)


remains present. The action lamp is not causing the fault. Go to Step 2.

2. CHECK FOR SHORT TO GROUND - Turn the disconnect switch to the OFF position. Wire 411-

PK remains disconnected from the action lamp. Disconnect the machine harness from the CMS

control. At the machine harness connector for the CMS control, measure the resistance between

contact 4 (411-PK) and frame ground.

* Resistance is less than 5000 Ohms; harness is defective. Repair or replace the machine

harness.

* Resistance is greater than 5000 Ohms; harness resistance is correct. Go to Step 3.

3. CHECK CONTROL - Remove contact 4 from the machine harness connector for the CMS control.

Reconnect the harness connector to the CMS control. Turn the disconnect switch to the ON position.

Put the system in service mode with CID 324 FMI 4F on-hold. Observe the fault present indicator.






harness connectors.

FMI 5F

This fault is recorded when the CMS control reads the current of the action lamp circuit (411-PK) as

below normal (open circuit). The result of this fault condition is that the action lamp does not light.



1. CHECK LAMP - Ensure that CID 324 FMI 5F is on-hold and that the fault present indicator shows

"SERV CODE". Observe the status of the fault present indicator or listen for the SOUNDING of the

action alarm. At the action lamp, use a jumper to connect wire 411-PK to frame ground.

* "SERV CODE" is NO longer shown or the action alarm SOUNDED; the lamp is open.

Replace the action lamp. (Note: For the purposes of this procedure, the correct resistance for a

lamp is less than 200 Ohms.)


remains present. The action lamp is not causing the fault. Go to Step 2.



2. CHECK HARNESS - Turn the disconnect switch to the OFF position. From Step 1; remove the

jumper and make sure the action lamp is connected to the machine harness. Disconnect the machine

harness from the CMS control. At the machine harness connector for the CMS control, measure the

resistance between contact 4 (411-PK) and frame ground.

* Resistance is greater than 100 Ohms; harness circuit is open. Go to Step 3.

* Resistance is less than 100 Ohms; harness circuit resistance is correct. Replace the CMS

control.

3. CHECK HARNESS - At the action lamp, disconnect wire 411-PK from the action lamp socket.

Check for an open in circuit 411-PK between contact 4 of the CMS harness connector and the lamp

socket. Also, check for an open in circuit 201-BK between the lamp socket and frame ground. Repair

or replace the harness.

CID 627 Procedure (Parking Brake Pressure Switch)

Service Notes: The connector contacts, which correspond to CID 627, are not shown on the CMS

contact identifier. The actual fault is present in either of the two parking brake pressure circuits.

Ensure that the fault present indicator shows "SERV CODE".

FMI 2F

This fault is recorded when the CMS control reads the parking brake pressure circuits as wrong.

CMS detects the status of the two parking brake pressure circuits. The status is correct, when one

circuit is open and one is grounded. The status is wrong, when both circuits are open or grounded at

the same time. Use status mode for troubleshooting these two switch type inputs; see the Undetected

Faults section.

Undetected Faults



Status Mode Display

(1) Status change identifier. (2) Open contact identifier. (3) Alert indicators with assigned numbers.

All the topics within this section (Undetected Faults) deal with switch type inputs. CMS does not

detect faults with switch type inputs. However, the diagnostics of status mode (mode 2) assist with

troubleshooting these faults. Status mode shows the open or grounded status of each switch input and

SOUNDS the action alarm when any switch input changes status. These status mode functions are

used extensively in the following procedures. When performing the procedures refer to the Status

Mode Diagnostics chart and the Status Mode Display illustration. For a detailed description of status

mode, see the topic Diagnostic Summary in the Testing And Adjusting section, or the topic Status

Mode (Mode 2) in the Systems Operation section.

Indicator Faults

Indicator faults are any faults that occur with the indicators of the CMS display area. The indicators

reflect the open or grounded status of the corresponding switch type inputs. A fault is when the

operation of an indicator does not correspond to a known machine condition. Indicator faults consist

of alert indicators and lighting indicators. Alert indicators are the indicators within the alert indicator

area on the right side of the CMS display. Lighting indicators (right turn, left turn and high beam) are

located in the center area of the CMS display.

Before troubleshooting, ensure that a fault does exist. For a description of what normal conditions

cause the alert indicators to FLASH and the lighting indicators to illuminate, see the machine

Operation & Maintenance Manual. Perform the following procedures only if a fault is suspected.

NOTE: One alert indicator is often used to indicate an electrical system problem. The alert indicator

for the electrical system gets information from sensor inputs, not switch inputs. See the topic Detected

Faults in the Testing And Adjusting section.

The operator or service person discovers an indicator fault when the operation of an indicator does not

correspond to a known machine condition. For example; the alert indicator for brake oil temperature



always FLASHES (even after overnight shutdown of the machine), or the high beam indicator is

never ON (even though the high beam headlamps are on). As observed during normal CMS operation,

the possible fault conditions for the indicators are:

* Alert indicator always FLASHING; see the Alert Indicator Always FLASHING procedure.

* Alert indicator never FLASHES; see the Alert Indicator Never FLASHES procedure.

* Lighting indicator always ON; see the Lighting Indicator Always ON procedure.

* Lighting indicator never ON; see the Lighting Indicator Never ON procedure.

NOTE: While in normal mode (mode 0), it is possible to troubleshoot indicator faults. The indicators

reflect the open or grounded condition of the uncommitted switch inputs and the lighting switch

inputs. When a switch input is open, the corresponding alert indicator FLASHES or the lighting

indicator is ON. When a switch input is grounded, the corresponding alert indicator or lighting

indicator is OFF. Therefore to check a circuit, the service person opens and grounds the

corresponding switch wire while watching for the correct result on the indicators.

Alert Indicator Always Flashing

This procedure is for an alert indicator that is FLASHING all the time. The always FLASHING

condition is most likely caused by an undesired open circuit or a defective CMS control (unlikely).

Procedure

1. Locate the switch which corresponds to the indicator which is always FLASHING. (If necessary,

use the Electrical System Schematic to assist in locating the switch.)

2. Place CMS in status mode (mode 2).

3. CHECK HARNESS - Disconnect the signal wire from the switch. Open and close the circuit

several times by touching the signal wire to the ground wire. (If a ground wire is not present, touch

the signal wire to frame ground.) Listen for the SOUNDING of the action alarm as the circuit is

opened and closed.

* The alarm SOUNDS; the circuit is operating correctly. The switch is defective. Check or

replace the switch.

* The alarm does NOT SOUND; the machine harness is open or the control is defective. Go to

Step 4.

4. CHECK FOR OPEN HARNESS - Turn the disconnect switch to the OFF position. At the machine

harness for the switch, place a jumper from the signal wire to the ground wire. (If a ground wire is not

present, jumper the signal wire to frame ground.)

On the Electrical System Schematic trace the signal wire from the switch to the CMS control.

Determine the signal contact (connector contact) of the machine harness at the CMS control.

Disconnect the machine harness from the CMS control. At the machine harness connector for the

CMS control, check for continuity between the signal contact and contact 2 (ground).

* Resistance is greater than 5 Ohms; the harness is defective. Repair or replace the harness.

* Resistance is less than 5 Ohms; the harness is not causing the fault. The control is defective.




Alert Indicator Never Flashes

This procedure is for an alert indicator that never FLASHES. The never FLASHING condition is

most likely caused by a short to ground or a defective CMS control (unlikely).

Procedure

1. CHECK ALERT INDICATOR - Perform the Self Test. Observe the alert indicators for

FLASHING during the Self Test. See Self Test.

* Alert indicator does NOT FLASH; the CMS control is defective. Replace the CMS control;

see CMS Control Replacement.

* Alert indicator FLASHES; the CMS control is not causing the fault. Go to Step 2.

2. Locate the switch which corresponds to the indicator which never FLASHES. (If necessary, use the

Electrical System Schematic to assist in locating the switch.)

3. Place CMS in status mode (mode 2).

4. CHECK SIGNAL WIRE - Disconnect the signal wire from the switch. Open and close the circuit

several times by touching the signal wire to the ground wire. (If a ground wire is not present, touch

the signal wire to frame ground.) Listen for the SOUNDING of the action alarm as the circuit is

opened and closed.

* The alarm SOUNDS; the circuit is operating correctly. The switch is defective. Check or

replace the switch.

* The alarm does NOT SOUND; the circuit is defective. The signal wire is shorted to ground.

Go to Step 5.

5. CHECK FOR OPEN HARNESS - Turn the disconnect switch to the OFF position. The signal wire

remains disconnected from the switch; do not allow it to touch anything.

On the Electrical System Schematic trace the signal wire from the switch to the CMS control.

Determine the signal contact (connector contact) of the machine harness at the CMS control.



* Resistance is greater than 5 Ohms; the harness is not causing the fault. The control is


* Resistance is less than 5 Ohms; the harness is defective. The signal wire within the harness is

shorted to ground. Repair or replace the harness.

Lighting Indicator Always ON

This procedure is for a lighting indicator (right turn, left turn or high beam) that is ON all the time.

The always ON condition is most likely caused by an undesired open circuit (burned out bulbs) or a

defective CMS control (unlikely).

NOTE: The usual cause for this Always ON condition, is that both bulbs of the circuit are burned out.

Check both related lamps before performing the following procedure. For the turn signal indicators,



check both corresponding right or left turn signal lamps. For the high beam indicator, check both high

beam head lamps.

Procedure

1. CHECK LIGHTING CIRCUIT - Check that both lamps (right turn, left turn or high beam) of the

related lighting circuit operate properly. Activate the related circuit (turn on the turn signal switch or

high beam head lamps). Observe the related lamps.

* Lamps illuminate; lighting circuit is not causing the fault. The signal wire within the harness

is open or the CMS control is defective. Go to Step 2.

* Lamps do NOT illuminate; lighting circuit is defective. Check lamps, fuses, switches, and

lighting ground path. Repair the circuit.

If the lighting circuit is fixed and the related lighting indicator remains always ON, Go to Step 2.

2. CHECK FOR OPEN SIGNAL WIRE - Turn the disconnect switch to the OFF position. Disconnect

the machine harness from a related lamp (right turn, left turn or high beam). At this connector place a

jumper from the lighting wire to the ground wire.

The signal wire connects the CMS control to the lighting circuit. The signal contact is the CMS

connector contact that corresponds to the signal wire. The signal contacts are:

High beam signal wire ... signal contact 6

Left turn signal wire ... signal contact 21

Right turn signal wire ... signal contact 22



* Resistance is greater than 5 Ohms; the harness is defective. Repair or replace the harness.

* Resistance is less than 5 Ohms; the harness is not causing the fault. The control is defective.


Lighting Indicator Never ON

This procedure is for a lighting indicator (right turn, left turn or high beam) that is never ON. The

never ON condition is most likely caused by a short to ground (therefore a blown fuse) or a defective

CMS control (unlikely).

Procedure

1. CHECK LIGHTING CIRCUIT - Check that both lamps (right turn, left turn or high beam) of the

related lighting circuit operate properly. Turn the disconnect and the key start switches to the ON

position. Activate the related circuit (turn on the turn signal switch or high beam head lamps).

Observe the related lamps.



* Lamps illuminate and lighting indicator remains OFF; lighting circuit is not causing the fault.

The CMS control is defective. Replace the CMS control; see CMS Control Replacement.

* Lamps do NOT illuminate and lighting indicator remains OFF; lighting circuit is shorted to

ground. Either the harness or the CMS control is defective. Go to Step 2.

2. CHECK FOR SHORT TO GROUND - Turn the disconnect switch to the OFF position. Disconnect

the machine harness from the CMS control. Check the machine harnesses for a short to ground in the

related lighting circuit. (The short to ground causes the fuse or circuit breaker to open.)

Also check the related CMS signal wire. The signal wire connects the CMS control to the lighting

circuit. The signal contact is the CMS connector contact that corresponds to the signal wire. Measure

the resistance between the signal contact and frame ground. The signal contacts are:

High beam signal wire ... signal contact 6

Left turn signal wire ... signal contact 21

Right turn signal wire ... signal contact 22

* Resistance is less than 5000 Ohms; harness is defective. Repair or replace the defective

harness.

* Resistance is greater than 5000 Ohms; harness resistance is correct. The CMS control is

defective. Verify that the CMS control is defective by; seeing if the related lamps on the

machine illuminate correctly with the CMS control disconnected. If so, replace the CMS

control; see CMS Control Replacement.

Display Brightness Fault

There are three different methods used to control the brightness of the CMS display area: automatic

method, display dimmer method and display brightness adjust method. Go to the method that

corresponds to the specific machine.

Automatic Method

On machines with the automatic method, the CMS control automatically controls the brightness

function; there are six brightness levels. A photosensor is located above the alert indicators within the

CMS display area. If the display is too dim, check the display area for something blocking the amount

of light available to the photosensor. Possible causes are: decal inadvertently placed over photosensor,

dirt or mud blocking photosensor.

Display Dimmer Method

On machines with the display dimmer method, the display dimmer switch (SPST) controls the

brightness function. The switch controls the dim input. When the input is grounded the display

brightness cycles; first the brightness decreases in steps to the minimum level, and then increases in

steps to the maximum level. The cycle repeats until the input is opened and then the brightness

remains at that level.



If the display brightness continuously changes without activating the switch or does not respond

correctly when the switch is activated, check the dim circuit. To troubleshoot the dim input, use status

mode. The CMS connector contact for the dim input is contact 5. Check for an undesired open or

grounded circuit in the harness wiring or the dimmer switch.

NOTE: On earlier CMS controls (when in status mode): To select the dim input (contact 5), ground

the clear input. Also, contact 5 corresponds to alert indicator No. 12.

Display Brightness Adjust Method

On machines with the display brightness adjust method, the display brightness switch (SPDT)

controls the brightness function. The switch controls the dim input and the brightness input. When the

dim input is grounded the brightness decreases in steps until the input is opened or till the minimum

level is reached. When the brightness input is grounded the brightness increases in steps until the

maximum brightness level is reached or until the input is opened.

If the brightness of the display does not function as described, check the dim circuit and the brightness

circuit. The dim input is at CMS connector contact 5. Determine the CMS connector contact that

correspond to the brightness input, use the Electrical System Schematic in the machine Service

Manual. To troubleshoot use status mode. Check for an undesired open or grounded circuit in the

harness wiring or the display brightness switch.

Gauge Method Fault

If the gauges change back and forth between single-segment and multi-segment methods or if the

wrong method is functioning, check the gauge method input. The multi-segment method functions

when the gauge method circuit is open. The single-segment method functions when the gauge method

circuit is grounded.

To troubleshoot the gauge method input, use status mode. The CMS connector contact for the gauge

method input is contact 19. Check for an undesired open or grounded circuit.

NOTE: On earlier CMS controls (when in status mode): To select the gauge method input (contact

19), open the clear input. Also, contact 19 corresponds to alert indicator No. 12.

Units Fault

If the unit indicators change back and forth between U.S. and metric units of measurement or if the

wrong units are shown, check the units input. U.S. units of measurement (mph) are shown when the

units input is open. Metric units of measurement (km/h) are shown when the units input is grounded.

To troubleshoot the units input, use status mode. The CMS connector contact for the units input is

contact 20. Check for an undesired open or grounded circuit.

NOTE: On earlier CMS controls (when in status mode): To select the units input (contact 20), ground

the clear input. Also, contact 20 corresponds to alert indicator No. 8.

Harness Code Fault



Status Mode Display

(1) Open contact identifier.

This procedure is only necessary if the CMS control has failed the Self Test. Before performing this

procedure, always perform the Self Test noting the machine code that is shown. Make sure the CMS

control has the correct part No. for the machine it is installed on. If the machine code is not shown

correctly this procedure determines which component is malfunctioning; defective CMS control,

wrong harness code or defective harness.

NOTE: Harness code and machine code are similar terms used to describe the particular machine that

the CMS control is installed on. Harness code is the status (open or ground) of the five harness code

inputs (connector contacts 25 through 29). Machine code is the number that CMS has assigned to a

particular harness code for a particular machine. The machine code is shown during the Self Test.

Each sales model has a specific harness code and therefore also a specific machine code. The specific

machine code is listed in the topic Self Test. The specific harness code is given in the Electrical

System Schematic module.

Status mode diagnostics are used to check the harness code that the CMS control is receiving. The

diagnostics assist in troubleshooting and reduce the continuity checks the service person performs to

"wring out" a harness. The following procedure determines the actual status (open or ground) of each

harness code input. The actual status must agree with the specified status (as listed in the Harness

Code Troubleshooting chart).

Procedure

1. Determine the machine code. The machine code is listed in the topic Self Test. After finding the

machine code, use the Harness Code Troubleshooting chart to find the corresponding specified

harness code.

If the machine code is NOT found (unknown), determine the harness code from the Electrical System

Schematic in the machine Service Manual. Then record the specified open or grounded status into the

row titled "Unknown" in the Harness Code Troubleshooting chart.

Go to Step 2.



2. Place CMS in status mode (mode 2). While in status mode, the status of all switch inputs (including

the harness code inputs) is shown on open contact identifier (1). Go to Step 3.

NOTE: On earlier CMS controls, ground the clear contact at the service connector to select the

harness code inputs.

3. Observe open contact identifier (1) for numbers 29, 28, 27, 26 and 25; any number shown is open,

any number NOT shown is grounded. Record the actual open or grounded status into the row titled

"Actual Status" in the Harness Code Troubleshooting chart. Go to Step 4.

4. From the chart, compare the specified status (Step 1) to the actual status (recorded in Step 3).

* Status agrees; the harness code is not causing the fault. Perform a Self Test again to recheck

the CMS control. If the CMS control still fails the self test, replace the control. See CMS

Control Replacement.

* Status does NOT agree; there is a defect in the harness code circuits that do not agree. Go to

Step 5.

5. CHECK FAULTY HARNESS CODE CIRCUITS - The remaining Steps make use of the

information obtained in Step 4 and recorded on the Harness Code Troubleshooting chart. The chart

identifies the connector contacts and wire identification of the harness code circuits. Further testing is

only necessary on the faulty harness code circuits.

* For contacts that are actually grounded but are specified open, there is a short to ground in the

corresponding harness code circuit. Go to Step 6.

* For contacts that are actually open but are specified grounded, there is an OPEN in the

corresponding harness code circuit. Go to Step 7.

6. CHECK FOR SHORTS - (For harness code circuits with corresponding contacts that are actually

grounded but are specified open). Turn the disconnect to the OFF position. Disconnect the machine

harness from the CMS control. At the machine harness connector for the CMS control, measure the

resistance between the corresponding faulty connector contact (25 through 29) and contact 2 (ground).

* Resistance is greater than 5000 Ohms; the harness code circuit is not shorted to ground. No

defect was found in the harness code circuits. Reconnect the harness connectors. Perform a Self

Test again to recheck the CMS control. If the CMS control still fails the self test, replace the

control. See CMS Control Replacement.

* Resistance is less than 5000 Ohms; the harness code circuit is shorted to ground in the

machine harness. Check the harness code plug on so equipped machines. Repair the shorted

harness code circuits or replace the harness.

7. CHECK FOR OPENS - (For harness code circuits with corresponding contacts that are actually

open but are specified grounded). Turn the disconnect to the OFF position. Disconnect the machine

harness from the CMS control. At the machine harness connector for the CMS control, check for

continuity between the corresponding faulty connector contact (25 through 29) and contact 2

(ground).

* Resistance is less than 5 Ohms; the harness code circuit is not open. No defect was found in

the harness code circuits. Reconnect the harness connectors. Perform a Self Test again to



recheck the CMS control. If the CMS control still fails the self test, replace the control. See

CMS Control Replacement.

* Resistance is greater than 5 Ohms; the harness code circuit is open. Check the harness code

plug on so equipped machines. Repair the open harness code circuits or replace the harness.

Electrical System Tests

When an electrical system problem is present, the alert indicator for the electrical system FLASHES.

These tests apply to warning category 1 or 3 problems. For a description of the warning indications

for an electrical system problem, see the topic Warning Operation in the Systems Operation section.

One of the following conditions cause the electrical system problem:

* The speed of the alternator is low; alternator "R" terminal frequency is less than 90 Hz. The

probable cause is a slipping belt or an internal alternator malfunction.

* System voltage (+battery) is too low. The probable cause is an excessive electrical load

(especially at low idle), alternator malfunction or defective batteries.

* System voltage (+battery) is too high. The probable cause is a defective alternator.

When engine speed is low, the operation of large electrical loads (such as air conditioning and/or

lighting) places a great demand on the charging system. If operating under these conditions, increase

the engine speed to high idle to generate more output from the alternator and then check the alert

indicator.

* If the alert indicator turns OFF within about one minute, the charging system is probably

overloaded while at low engine speed. To correct the problem, change the machine operation by

increasing the engine speed and/or decreasing the electrical load (use medium or low fan speed

instead of high).

* If the alert indicator remains FLASHING, there is a malfunction that requires service.

Perform the Electrical System Troubleshooting procedures.

Electrical System Troubleshooting

Procedure

1. VISUAL CHECK - Check the alternator belt pulley and the belt tension.

* Pulley nut torque and belt tension are proper; go to Step 2.

* Pulley and belt are NOT proper; fix or adjust.

2. CHECK BATTERY VOLTAGE - Measure the battery voltage at the battery posts.

* Voltage is between 24.8 and 29.5 DCV; battery voltage is correct. Go to Step 3.

* Voltage is NOT between 24.8 and 29.5 DCV; there is a defect in the electrical system. Check

the charging system, go to Charging System Test.

3. CHECK SYSTEM VOLTAGE HARNESS CIRCUIT - Turn the key start switch to the OFF

position. Disconnect the machine harness from the CMS control. Start the engine and run at high idle.



At the machine harness connector for the CMS control, measure the voltage between contact 7

(system voltage circuit) and contact 2 (ground).

* Voltage is between 24.8 and 29.5 DCV; system voltage is correct. Go to Step 4.

* Voltage is NOT between 24.8 and 29.5 DCV; there is a defect in the harness. Repair or

replace the harness.

4. CHECK "R" TERMINAL HARNESS CIRCUIT - Start the engine and run at high idle. At the

harness connector, measure the voltage between contact 12 (alternator "R" terminal circuit) and

contact 2 (ground).

* Voltage is between 12.4 and 14.75 DCV; the "R" terminal voltage is correct. Replace the

CMS control; see CMS Control Replacement.

* Voltage is NOT between 12.4 and 14.75 DCV; there is a defect in the harness. Repair or

replace the harness.

Charging System Test

Procedure

1. Put the multimeter positive (+) lead on the Bat terminal of the alternator. Put the negative (-) lead

on the ground terminal or the frame of the alternator. Put the clamp-on ammeter around the positive

output wire of the alternator.

2. Turn off all electrical accessories. With the fuel off, crank the engine for 30 seconds. Wait two

minutes to let the starting motor cool. If it is believed that the batteries are fully charged, crank the

engine again for 30 seconds.



NOTE: Cranking the engine for 30 seconds partially discharges the battery in order to do a charging

test. If the battery is already low in charge, skip this step. Jump-start engine or charge as required.

3. Start the engine and run at full throttle.

4. Immediately check output current. For correct operation, this initial charging current is equal to or

slightly greater than the full output current shown below:

5S9088 Alternator ... 50A

8N0999 Alternator ... 75A

5. For correct operation, within approximately 10 minutes at full throttle (possibly longer depending

upon battery size, condition and alternator rating), the alternator output voltage is 26.5 to 29.0 DCV.

See the Fault Conditions And Possible Causes chart.

6. The charging current during this period should taper off to less than approximately 10 amps with

accessories turned OFF, depending again upon battery and alternator capacities. See the Fault

Conditions And Possible Causes chart.

7. Turn on all electrical accessories. The alternator must maintain 26.5 to 29.0 DCV. The ammeter

shows total charging current.

Speed Sensor Test

Portion Of CMS Control - From Machine Schematic

NOTE: More than one speed sensor exists for the different applications of CMS. One sensor has a

nominal resistance of 150 Ohms and the other has a nominal resistance of 500 Ohms.

The following procedure is useful if the speed indication on the speed gauge or speed readout is

faulty. For example; the speed shown is 0 RPM when the engine is running or shows 0 MPH when the

machine is moving.

To use the procedure it is necessary to know the CMS connector contact that corresponds to the fault.

The engine RPM and ground MPH (km/h) inputs are frequency type sensor inputs. CMS connector

contacts 10 and 11 are the frequency sensor inputs. Use the Electrical System Schematic in the

machine Service Manual to determine the CMS connector contact that corresponds to engine RPM



and ground MPH (km/h). For example according to the above illustration; engine speed (ENG RPM)

corresponds to connector contact 11, ground speed (XMSN RPM) corresponds to connector contact

10.

NOTE: The diagnostics of the CMS do not detect faults in the speed circuits (frequency sensor).

Procedure

Speed Sensor

1. CHECK SENSOR RESISTANCE - Turn the disconnect switch to the OFF position. Disconnect the

machine harness from the sensor. At the machine harness connector, for the sensor, measure the

resistance between the two contacts.

* Resistance is NOT between 100 and 600 Ohms; the speed sensor is defective. Replace the

sensor. Adjust the speed sensor properly when installing it. See Speed Sensor Adjustment.

* Resistance is between 100 and 600 Ohms; the speed sensor resistance is correct. Go to Step 2.

2. CHECK SENSOR VOLTAGE - Reconnect the sensor to the machine harness. Disconnect the

machine harness from the CMS control. Start the engine and run at low idle. At the machine harness

connector, for the CMS control, measure the voltage (ACV) between contact 2 (ground) and contact

10 or 11.

* Voltage is greater than 3.0 ACV; the speed sensor voltage is correct. Replace the CMS

control; see CMS Control Replacement.

* Voltage is less than 3.0 ACV; the speed sensor voltage is NOT correct. Go to Step 3.

3. CHECK SENSOR ADJUSTMENT - Check the speed sensor adjustment, see Speed Sensor

Adjustment. Perform Step 2 again.

* Voltage remains less than 3.0 ACV; there is a defect. Go to Step 4.

* Voltage is now greater than 3.0 ACV. Problem is NOT present; adjustment of the speed

sensor corrected the problem.

4. CHECK HARNESS - Connect the sensor to the machine harness. The CMS control remains

disconnected from the machine harness. At the machine harness connector, for the CMS control,

measure the resistance between contact 2 (ground) and contact 10 or 11.



* Resistance is between 100 and 600 Ohms; the machine harness resistance is correct. Replace

the sensor. Adjust the speed sensor properly when installing it. See Speed Sensor Adjustment.

* Resistance is NOT between 100 and 600 Ohms; the machine harness is shorted or open.

Repair or replace the harness.

Speed Sensor Adjustment

Speed Sensor

(1) Air gap. (2) Locknut.

1. Remove the speed sensor. Align a gear tooth directly in the center of the threaded sensor opening.

2. By hand, screw the sensor into the hole until the end of the sensor just makes contact with the gear

tooth.

3. Turn the sensor back out 1/2 turn (180 in the counterclockwise direction). This sets air gap (1) to

0.89 mm (.035 in).

4. Tighten locknut (2) to 13 1 Nm (115 9 lb in).

NOTE: Do not allow the sensor to turn as locknut (2) is tightened.

PWM Sensor Tests



NOTE: In addition to these tests, CMS diagnostics are helpful when troubleshooting sensors.

Numeric readout mode diagnostics show a numeric value of the information from each sensor input.

For a detailed explanation, see the topic Numeric Readout Mode (Mode 4) in the Systems Operation

section.

Troubleshoot sensor circuits in the following order.

1. Perform Sensor Voltage Test. The test checks sensor voltages at the sensor with all circuits

connected. DISCONNECT NOTHING. Troubleshoot "as is" before disconnecting any circuits.

Disconnecting first may alter a poor connection and make proof-of-cause difficult or impossible.

2. Perform Sensor Dynamic Test.

3. If sensor and harness check correctly, the CMS control is likely defective. Replace the CMS

control, see CMS Control Replacement.

To identify sensor wires and connector contacts, refer to the following Sensor Wire And contact

Identification section. Otherwise proceed to Sensor Voltage Test

Sensor Wire And Contact Identification

Typical PWM Sensor - Schematic Symbol

When testing a sensor, it is necessary to identify the connector contacts and the harness wires. The

Electrical System Schematic shows the connector contact No.'s which correspond to the wire

numbers. See the Electrical System Schematic in the machine Service Manual.

On all machines, the wire numbers and connector contacts are identified by these general rules:

* The +V wire number (power) is between 100 and 199. The +V contact corresponds to this

wire number.



* The ground wire number is between 200 and 299. The ground contact corresponds to this

wire number.

* The signal wire number is between 400 and 499. The signal contact corresponds to this wire

number.

For example, in the above Typical PWM Sensor illustration:

The +V wire is wire number 113.

The +V contact is contact A.

The ground wire is wire number 201.

The ground contact is contact B.

The signal wire is wire number 443.

The signal contact is contact C.

Sensor Voltage Test (CMS Control Connected)



Procedure

Locate the suspect sensor. Identify the sensor wires and connector contacts; see Sensor Wire And

Contact Identification. DO NOT DISCONNECT ANY HARNESS CONNECTORS AT THIS TIME.



Turn the key start switch to the ON position. DO NOT START THE ENGINE. Use the 7X1710

Cable Probe (Spoons) to make voltage measurements by probing through the back of the harness

connectors.

1. CHECK SYSTEM VOLTAGE - Between the sensor and the sensor connector, identify the +V and

ground circuits. Use the 7X1710 Cable Probe (Spoons), measure the system voltage between the +V

and ground wires.

* Voltage is between 24.0 and 29.5 DCV; system voltage is present. Go to Step 2.

* Voltage is NOT between 24.0 and 29.5 DCV; there is an open circuit. Trace the +V and

ground circuits in the machine harness. Repair or replace the harness.

2. CHECK SIGNAL VOLTAGE - Between the sensor and the sensor connector, identify the signal

and ground circuits. Use the 7X1710 Cable Probe (Spoons), measure and record the signal voltage

between the signal and ground wires.

NOTE: If more precise signal voltage specifications are necessary, use the specifications listed in the

Sensor Voltage Specifications at the beginning of this test.

* Voltage is between approximately 1.0 and 7.0 DCV; signal voltage at the sensor is correct.

Go to Step 3.

* Voltage is NOT between approximately 1.0 and 7.0 DCV; signal voltage is not correct.

If voltage is greater than 7.0 DCV, Go to Step 4.

If voltage is less than 1.0 DCV, Go to Step 5.

3. CHECK MACHINE HARNESS SIGNAL CIRCUIT - At the machine harness for the CMS

control, identify the signal and ground circuits. DO NOT DISCONNECT THE HARNESS

CONNECTOR. Use the 7X1710 Cable Probe (Spoons), measure and record the signal voltage

between the signal and ground wires. Compare this measurement with the voltage measured in Step 2.

* Voltage is the same as in Step 2; the CMS is receiving a valid signal voltage. If the problem

still persists, further testing is required; see Sensor Dynamic Test.

* Voltage is NOT the same as in Step 2; the machine harness has an open in the signal or

ground circuits. Repair or replace the machine harness.

4. CHECK MACHINE HARNESS - Signal voltage is greater than 7.0 DCV. The probable cause is a

short to system voltage (+battery) in the machine harness or the sensor is defective. Disconnect the

machine harness from the sensor. At the machine harness connector for the sensor, measure the

voltage between the signal contact and the ground contact.

* Voltage is greater than 5.0 0.5 DCV; the voltage is not correct. The signal circuit of the

machine harness is shorted to +battery. Repair or replace the machine harness. If the machine

harness is not defective, replace the CMS control.

* Voltage is 5.0 0.5 DCV; the voltage is correct for a good harness. The sensor is defective.

Replace the sensor.

NOTE: Fuel level sensors consist of a buffer and a sender. Before replacing either, check the sender.

See Fuel Level Sender Check.



5. CHECK MACHINE HARNESS - Signal voltage is less than approximately 1.0 DCV. The

probable cause is a short to ground in the machine harness or the sensor is defective. Disconnect the

machine harness from the sensor. At the machine harness connector for the sensor, measure the

voltage between the signal contact and the ground contact.

* Voltage is less than 5.0 0.5 DCV; the voltage is not correct. The signal circuit of the

machine harness is shorted to ground. Repair or replace the machine harness. If the machine

harness is not defective, replace the CMS control.

* Voltage is 5.0 0.5 DCV; the voltage is correct for a good harness and CMS control. The

sensor is defective. Replace the sensor.

NOTE: Fuel level sensors consist of a buffer and a sender. Before replacing either, check the sender.

See Fuel Level Sender Check.

Sensor Dynamic Test (CMS Control Disconnected)



Pgina 44 de 53966F Series II Wheel Loader 1SL00507-UP (MACHINE)

Codigo de Fallas Payloader PAYLOADER 966G

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