Gearbox, I–Shift, Generation D Design and Function

Service BulletinVolvo Truck CorporationGteborg, Sweden Trucks

Date Group No. Release Page

12.2010 431 303 04 1(32)

Gearbox, IShift, Generation D

Design and function

FH/FM

AT2412D, AT2612D, AT2812D,ATO2612D, ATO3112D

Gearbox, IShift, design and function

T4021207

The service information describes the design and function of AT gearboxes.

88981349ENG42953 English

Printed in Sweden

Volvo Truck Corporation Date Group No. Release PageService Bulletin 12.2010 431 303 04 2(32)

Gearbox, mechanicalI-Shift, Generation D

Contents General, page 3 Gear ratio, page 4 Gearbox construction, page 4 Synchronisation, page 6 Range housing, page 6 Range gear, page 6 Emergency steering servo pump, page 7 Oil cooler, page 7 Control housing, page 8 Countershaft brake, page 9 Clutch cylinder, page 10 Lubrication system, page 10 Ventilation, page 13 Electrical system, page 14 Compressed air system, page 16 Power train, page 17 Auxiliary brake lever, page 23 Gear shifter, page 24 Display, page 24 Program packages, page 25 Function description, page 27 Communication with other control units, page 30


General

T4021207

Make VOLVO

Type

AT2412DAT2612DAT2812DATO2612DATO3112D

Unsynchronized main gearbox

Special markings ATO2612D

A - AutomaticT - TransmissionO - Overdrive26 - Torque 2600 Nm12 - Number of forward gearsD - Generation

Range gear Synchronised

Split gear Synchronised

Forwards 12Number of gears

Reverse 4

AT2412D, AT2612D, ATO2612D AT2812D, ATO3112D

Dry weight 271 kg 277 kg

Length 891 mm 909 mm


Gear ratioEngaged gear AT2412D, AT2612D, AT2812D ATO2612D, ATO3112D

1st 14,94:1 11,73:1

2nd 11,73:1 9,21:1

3rd 9,04:1 7,09:1

4th 7,09:1 5,57:1

5th 5,54:1 4,35:1

6th 4,35:1 3,41:1

7th 3,44:1 2,70:1

8th 2,70:1 2,12:1

9th 2,08:1 1,63:1

10th 1,63:1 1,28:1

11th 1,27:1 1,00:1

12th 1,00:1 0,79:1

Reverse gear (R1) 17,48:1 13,73:1

Reverse gear (R2) 13,73:1 10,78:1

Reverse gear (R3) 4,02:1 3,16:1

Reverse gear (R4) 3,16:1 2,48:1

Gearbox constructionThe gearbox construction consists of three main parts:a clutch housing, a basic housing and a range housing.The clutch housing forms the front end plate of thegearbox. The base housing contains the main, counter

and reverse shafts along with a selector unit which isintegrated into the control housing. The range housingcontains the range gear planetary gear and the outputshaft.

T4021405

1 Clutch housing

2 Main housing

3 Range housing for the retarder

The main parts in the gearbox are the input shaft, mainshaft, range gear with selector unit, countershaft, oil

pump with reverse shaft, as well as the control housingwith selector unit.


The trailing wheels for the reverse gear and basic gearsare located on the main shaft. The range gears sun gearis also integrated with the main shaft. The countershafthas fixed gears.

The range gear incorporates a planetary gear and isintegrated with the output shaft.

Gearboxes equipped with a power take-off also have adrive shaft fitted.

T4021728

1 Input shaft

2 Main shaft

3 Range gear with selector unit and retarder drive

4 Countershaft

5 Oil pump with reverse shaft

6 Control housing with selector unit

7 Drive shaft for power take-off


Synchronisation Split gear (A) is synchronized. The main gearbox housing (B) with its gears is not

synchronized.

Range gear (C) is synchronized.

T4021404

Range housingRange housing (C) can be combined with:

Power take-off; see option instructions for variants Emergency steering servo pump Retarder unit

Range gearThe range synchronising is located outside the ring gearwhich reduces the units length. The large synchronisingarea makes for short gear-shift times and the wide planet

gears with their helical teeth contribute to a robust andsilent planet gear.

T4021725

Range gear with selector unit and retarder drive


Emergency steering servo pumpThe emergency steering servo pump is located on thegearbox and is driven by the gearbox output shaft. Theemergency steering servo pump is activated when forsome reason the normal power steering circuit fails.

T4021683

Emergency steering servo pump, PSS-DUAL

Oil cooler

T4021755

The gearbox oil cooler function is not affected by whether the gearbox has a retarder or not.


Control housingGears are selected using the gear selector. Once a gearhas been selected, the system reduces the engine torqueto a suitable level, after which the gears are shifted toneutral.

After the gearbox has been put into neutral, the enginespeed is adjusted to accommodate the speed of theselected gear, after which the gear shift takes place.

The control housing cover has two or sometimesthree electrical sockets.

When there is no retarder, the following applies:

I Vehicle communication

II Clutch cylinder

III

The following applies with retarder:

I Vehicle communication

II Retarder

III Clutch cylinder

T4018492

The control housing incorporates nine solenoidvalves:

2. Solenoid valve 2nd gear

LR. Solenoid valve, low range

3. Solenoid valve 3rd gear

HR. Solenoid valve, high range

B. Solenoid valve, brake

HS. Solenoid valve, high split1

R. Solenoid valve, reverse

LS. Solenoid valve, low split1

1. Solenoid valve 1st gear

1 HS and LS have reversed functions on Over Drive gearboxes.

T4018189

The control housing incorporates the followingcomponents:

Four parallel cylinders, split, 1/R and 2/3 and range. Four inductive sensors for the positioning of the

pistons.

Two speed sensors, one for the main shaft and onefor the countershaft. The input shaft speed is set bythe countershaft sensor.

An oil temperature sensor, selector forks for splitgears and main gearbox. The oil temperature sensoris located on the cabling for the rpm sensor.

A pressure sensor. Control unit for transmission, TECU.

T4018494

Locations of cylinders and position sensor


A. Split cylinder

B. 1/R cylinder

C. 2/3 cylinder

D. Range cylinder

E. Position sensor for the split cylinder

T4018201

Location of position sensor and speed sensor

A. Position sensor range cylinder

B. Speed sensor, countershaft

C. Speed sensor, main shaft

D. Position sensor, 2nd and 3rd cylinders

E. Position sensor 1st and reverse cylinder

Countershaft brakeThe counter shaft brake is located at the front of thecounter shaft and brakes the rotating parts the gearboxwhen a start gear is selected, which eliminates gearboxwear, deposits and noise. The brake is also sometimesused during changing up to give quicker gear changes. Itis activated using an integrated pneumatic cylinder.

T4021408

Countershaft brake


Clutch cylinderThe clutch cylinder is located in the clutch housing,concentrically round the input shaft with a position sensorwhich measures clutch wear. A valve unit controls theclutch cylinder and is located on the outside of the clutchhousing.

T4021655

A. Clutch cylinder

B. Position sensor

C. Valve unit

D Bleeder nipple for the valve unit.

Lubrication system

T4023570


The gearbox is lubricated through a combination ofpressure and splashing.

The oil is led into the main shaft to lubricate and cool therange gears as well as the input and main shaft bearings.

The countershaft brake, output shaft bearings, emergencysteering servo pump drive, retarder gear and powertake-off are also lubricated.

The lubrication system has two overflow valves. Onevalve ensures that the gearbox is lubricated if thefilter gets blocked while the other prevents excessivepressures in the system, e.g. during cold start. The valvesare made up of a compression spring and a valve peg. T4021730

The overflow valve which ensures the gearbox is lubricated

if the filter gets blocked.

T4021729

Overflow valve which prevents excessive pressure.

Oil pumpThe oil pump is an eccentric pump driven by thecountershaft via a gear. The pump is mounted in twoneedle bearings in the reverse shaft.

There is a full flow oil filter of the insert filter type on thepressure side of the pump. It is located in the oil filterhousing in the main housing. A support pipe is fittedin a cover that is fastened to the bottom of the oil filterhousing. The support pipe prevents the filter, which sitson the outside, from collapsing.

T4021520


Oil levelThe oil level is checked using a level glass (2) and isadjusted through two drain plugs (1A and 1B) and twofiller plugs (3 and 4).

Overfilled oil is also adjusted with a level plug (3).

Read more about oil quality and oil change volumesinFunction Group 1750, Information type Service andmaintenance Preventive maintenance intervals.

T4021684

Level glass to check oil level

T4033600

The previous version

1A. Drain plug

1B. Drain plug

2. Sight glass

3. Filler plug/level plug

4. Filler plug/air valve

T4033602

The later version

1A. Drain plug

1B. Drain plug

2. Sight glass

3. Filler plug/level plug

4. Filler plug


VentilationThe ventilation in the previous version runs through ahose that goes past the control housing and down behindthe valve assembly.

T4021686

The previous version

The ventilation in the later version runs through a built-inair duct with two valve holes on the main housing.

T4033605

The later version


Electrical systemSensors and sockets, for gearboxes without a retarder

T4021412

I. Vehicle communication

II. Clutch cylinder

A. Speed sensor

T4021413

Cabling from socket I to the speed sensor andchassis cabling.

T4021414

Cabling from socket II to the valve unit for theclutch cylinder.


Sensors and sockets, for gearboxes with a retarder

T4021409

I. Vehicle communication

II. Retarder

III. Clutch cylinder

A. Speed sensor

T4021411

Cabling from socket I to the speed sensor andchassis cabling.

T4021410

Cabling from socket II to the retarder.

T4021418

Cabling from socket III to the valve unit for theclutch cylinder.


Compressed air systemCompressed air connections

T4021415

Compressed air connection between the control housing

and the valve unit for the clutch cylinder.

T4021416

For the high pressure system, compressed air connection

between the control housing and the four-circuit valve.

For the low pressure system, compressed air connection

between the control housing and the pneumatic tank.

T4023619

Pneumatic connection between the control housing and the

countershaft brake.


Power trainThe following illustrations show the driveline for AT2412D,AT2612D and AT2812D.

T4021693

1st gear

T4021694

2nd gear

T4021695

3rd gear

T4021696

4th gear

T4021697

5th gear

T4021698

6th gear


T4021699

7th gear

T4021700

8th gear

T4021701

9th gear

T4021702

10th gear

T4021703

11th gear

T4021704

12th gear


T4021691

Neutral N1

T4021692

Neutral N2

T4021687

Reverse gear (R1)

T4021688

Reverse gear (R2)

T4021689

Reverse gear (R3)

T4021690

Reverse gear (R4)


The following illustrations show the driveline forATO2612D and ATO3112D.

T4021711

1st gear

T4021712

2nd gear

T4021713

3rd gear

T4021714

4th gear

T4021716

5th gear

T4021715

6th gear


T4021717

7th gear

T4021718

8th gear

T4021719

9th gear

T4021720

10th gear

T4021721

11th gear

T4021722

12th gear


T4021709

Neutral N1

T4021710

Neutral N2

T4021705

Reverse gear (R1)

T4021706

Reverse gear (R2)

T4021707

Reverse gear (R3)

T4021708

Reverse gear (R4)


Auxiliary brake leverOn all vehicles with a retarder and on vehicles with anautomatic gearbox and engine brake (VEB) the auxiliarybrake is applied using a lever on the steering shaft.

0 Auxiliary brake not applied

A Automatic mode

13 Manual mode

B Position for activating the brake program. Spring returnto position 3.

T5015517

The illustration shows a vehicle with the Basic programpackage which does not contain a brake program. Whenthe auxiliary brake lever is moved to position B, thegearbox selects a gear that gives an engine speed justabove 1500 rpm. If the speed is reduced, the gearboxselects gears that maintain an engine speed between1000 and 1500 rpm. (B). The driver can also change downfurther by moving the auxiliary brake lever to position B.Read more about Program packages, page 25.

T4022470

Without the brake program, (A) desired rpm for first change

down, (B) area for braking using the auxiliary brake.

The vehicle in the illustration is equipped with one of theprogram packages Distribution & Construction, LongHaul & Economy or Heavy Duty, which contains thebrake program. When the auxiliary brake lever is movedto position B, the gearbox selects a gear that gives anengine speed above 1500 rpm. The gearbox then selectsgears that maintain an engine speed above 1500 rpm.(B). Read more about Program packages, page 25.

T4022471

With the brake program, (B) area for braking using the

auxiliary brake.

Note: The auxiliary brakes effect can be reduced bythe I-shift control unit, MID 130, to make driving ascomfortable as possible. The reduction in effect iscontrolled by the selected gear, the weight of the vehicleand the inclination of the road surface. The brake effect isnot, however, reduced while in manual mode.

For more information on auxiliary brake component parts,see group 21, Description, Design and Function, Engine.


Gear shifterGear selector (GLU) is attached to the drivers seat andcan be folded away to ease passage inside the cab. Thegear selector control unit is in the dashboard.

The gear selector incorporates the following functions:

1 Three position switch with spring return for up anddown changing.

2 Button for lowering the lever into a horizontal position.

3 Gear selector inhibitor preventing the vehicle frombeing put in gear unintentionally.

4 Gear selector position:

R = Reverse. Changing up and down is done usingthe +/- button on the gear selector.

N = Neutral. No gear engaged.

A = Automatic mode. The gearbox will automaticallyselect the correct gear with respect to load, incline,speed and throttle.

M = Manual mode. Changing up and down is doneusing the +/- button on the gear selector.

F = The gear lever is tilted (folded).

5 Button E/P/P+/HD

E = Economy mode

P = Power mode

P+ = Enhanced power mode, optional function(included in AVO-ENH, see Variant of possibleoptional functions, page 26

HD = Heavy Duty part of the heavy transport programpackage, TP-HD, see Program packages, page25). Activate/inactivate the function by pressing in thebutton for at least three seconds.

6 Button L, Limp Home. The function is intended formoving the vehicle short distances so that one candrive off the road or to a workshop. When Limp homeis selected, it is not possible to drive if the gear selectoris in position A. Only gears 1, 3 and 5 forwards and 1reverse can be used. Gear shifting is only possiblewhen the truck is stationary.

T4022483

DisplaySelect the GAUGES menu in the display to viewinformation about I-Shift (applies to both stationaryvehicles and when driving). Information about thegearbox is then shown in the driver display.

The gearbox field is divided into smaller sections showing:

1 Driving program

2 Selected gear

3 Available gears (down/up)

4 Selector position

T3018210


Program packagesGeneral notes about the program packagesThe gearbox has different characteristics and functionsdepending on the program package that is installed. Thefollowing program packages are available:

BasicStandard program for gearboxes

Distribution & ConstructionIncludes functions that make the truck easier tomanoeuvre, e.g.:

brake program

several functions that work together with EBS

Long Haul & Economy includes functions thatcontribute to improved fuel economy and also makethe truck easier to manoeuvre. In addition to the samefunctions as the Distribution & Construction packagethere is also a freewheel function I-roll and Smartcruise.

Heavy Duty is aimed at heavy transports. Driveabilityand comfort are optimised for heavy weights, but themode can be deselected for lighter loads to improvefuel consumption and give better comfort.

Program package variantsProgram packages VDA variants Display

Basic TP-BAS B

Distribution &Construction

TP-DICON DC

Long Haul & Economy TP-FUEC FE

Heavy Duty transports TP-HD HD

When the gear selector is in neutral position (N) andthe FOLD button is pressed in, the lever can be tiltedforwards. The display then shows the program variantof the gearbox. For this, gearbox information must beselected as favourite in the display.

Change program packageWhen a program package is replaced, the Central system(VDA) must be updated before it can be downloadedto the vehicle. This is done by entering the Convertingset number in the computer tool which is stated in Partinformation, accessory.

After replacement, reprogramming must be carried outusing the TECU control unit (MID 130), and the gearboxmust be recalibrated.


Functions in program package, generalBasic is the standard program and the other programsinclude extra equipment. Which options that can bechosen depends on which program package that hasbeen chosen. See table below.

(X) = Standard(O) = Option() = Not selectable

Program packages

FunctionsTP-BAS TP-DICON TP-FUEC TP-HD1

Basic Power Take Off Functions X X X X

Basic Gear SelectionAdjustment

X X X X

Basic Vocational Functions X X X X

Basic Shift Strategy X X X X

Performance Shift X X X X

Gearbox Oil TemperatureMonitor

X X X X

Heavy Start Engagement X X X X

Enhanced Shift Strategy X X X

Launch Control X X X

I-Roll X X

Smart Cruise Control X X

Heavy Duty GCW Control X

Possible optional functions

Enhanced Power Take OffFunctions

O O O O

Enhanced Gear SelectionAdjustment, incl. Kick-down

O O O

Enhanced Performance BadRoads

O O O

1 Only AT2612D and ATO3112D

Variant of possible optional functions

Functions Variant Installed Not installed

APF-ENH XEnhanced Power Take Off Functions

APF-BAS X

AMSO-AUT XEnhanced Gear Selection Adjustment, incl. Kick-down

AMSO-BAS X

AVO-ENH XEnhanced Performance Bad Roads

AVO-BAS X


Function descriptionFunctions Basic Power Take Off Functions

Facilitates power take-off operation. Pre-definedsplit gear positions determine which split gear is tobe engaged when one or two power take-offs areconnected. As the choice of gear is adapted to theengine speed limitation, software parameters canbe set. Then the selection of gear is adapted toany limitation of the engine speed due to bodyworkfunctions.

Basic Gear Selection AdjustmentProvides the possibility to adjust gear selection withthe gear selectors buttons while engine braking inautomatic mode.

Basic Vocational FunctionsProvides the possibility to choose between the drivingmodes Economy and Performance.

Basic Shift StrategyAutomatic choice of starting gear. The gearbox selectsthe most suitable starting gear based on weight andthe gradient of the road, also in manual mode.

Performance ShiftAllows adjustment of automatically selected gear whenengine braking.

Gearbox Oil Temperature MonitorShows the gearbox oil temperature in the informationdisplay.

Heavy Start EngagementStart with higher engine speed in power mode in 1st,which gives a higher starting torque. The functionincreases the engine speed to facilitate heavy starts.This is useful e.g. when the truck is stuck in softsurfaces.

Enhanced Shift StrategyWorks together with the ECS and EBS to select thecorrect gear for smooth movement on surfaces difficultto manoeuvre or to get the maximum effect of theauxiliary brakes.

Temporarily applies the wheel brakes when changinggear to compensate for the engine brake whenthe brake program is active. This function requiresABS-EBS. If a trailer without ABS is hitched up, thefunction is deactivated.

Launch ControlAllows the engine to drive the wheels at idle, which canbe useful e.g. when driving in traffic queues.

Regulates engine torque when pulling away foroptimum gear changing and avoid high engine speed.

The following functions require EBS:

Improved comfort when pulling-up through smootherdisengagement when pressing lightly on the brakepedal.

Automatic application of the brakes when the vehiclerolls in the wrong direction, in relation to the selectedgear.

Automatic application of the brakes to stop the vehicleand change from a forward to a reverse gear or viceversa.

HSA, Hill start assistance, which is only active oninclinations. See also the description of hill startassistance: Function group 593, Information typeDescription Electronically controlled braking system(EBS).

I-Roll (requires VEB/VEB+ or retarder)Automatic engagement and disengagement of thefreewheel function, with the aim of reducing fuelconsumption. When the accelerator pedal is released,the driveline is disconnected so that the vehicle canroll freely, and the engine is brought down to its idlingspeed.

Inactivate I-Roll by pressing the minus button or bymoving the auxiliary brake lever to the 0 position.

Smart Cruise ControlOnly active when the cruise control is activated. Savesfuel by, in certain modes, deactivating the auxiliarybrakes. The function improves the cruise controlfunction by releasing the auxiliary brakes at the endof downhill slopes.

Heavy Duty GCW Control (HD)Matches gear change strategy and clutch operationsfor high total weights (>85 tonnes).

The I-Roll function is inactivated automatically whenthe HD function is activated.

The function always selects 1st gear as starting gear.


Possible optional functions Enhanced Power Take Off Functions

Optional functions that make it possible to supportpower take-off functions.

Optional functions:

Makes it possible to determine software parametersthat limit engine speed when power take-off is used.The function forms a gear selection strategy to suitengine speed limitations.

Disengages the transmission at the request of theoptions module, irrespective of the gear lever position,when Auto Neutral is activated.

Blocks reverse gear when the options module requests reverse inhibit.

Makes it possible to use the splitbox for driving thepower take-off at high capacity.

Enhanced Gear Selection Adjustment in Auto incl.Kick-downEnables selection of gears in automatic mode evenwhen the accelerator pedal is depressed. There is alsoa Kick-down function for maximising the accelerationof the truck.

It is possible to change up and down while driving atidle in Auto-mode.

Enhanced Performance Bad Roads (P+)Extended performance program for difficult conditionson i.e. poor roads in forests, construction sites oroff-road driving.

Improved ability to drive away when the vehicle is stuckby using the engines inertia to obtain higher torque.

Greater margins before changing up give safer gearshifts on varying road inclinations.

With unusually steep uphill slopes, the driver canchange down several steps by moving the gearselector to manual mode and pressing the minusbutton at the same time.

Adjusts gear changes faster to the variations ininclinations.

The kick-down function is inactivated with off-roaddriving to prevent unintentional down-changing.


Customer parametersCustomer parameters in the gearbox control unit: Note: The default value can vary depending on the

program package selected.

ID Designation Default Value Unit

GJJ

States that the engines power take-off can be loaded even whenit is inactivated.By setting this parameter to "Yes" the gear change qualityproblem is solved as the engines rear power take-off is alwaysactivated.

No Yes / No

GJIAuto Neutral via the clutch.The clutch is used to inactivate the gearbox under AutoNeutral.1

No Yes / No

GJG

States how the split gear behaves when power take-off 1 isactivated.Low split has priority over high split if both power take-offs 1 and2 are activated and have conflicting split gear settings.

Selectable LS / HS / Selectable

GJH

States how the split gear behaves when power take-off 2 isconnected for the gearbox.Low split has priority over high split if both power take-offs 1 and2 are activated and have conflicting split gear settings.

Selectable LS / HS / Selectable

IEO

States how the gearbox power mode is handled.Manual = Power mode available.Auto = Power mode available. The gearbox returnsautomatically to economy mode when the engine is no longerunder heavy load.Inactivate = Power mode is not available.

AVO-ENH =Inactivated

AVO-BAS = Auto

Manual / Auto /Inactivated

IEH States when the kick-down function is available.

AMSO-BAS =not availableAMSO-ENH =always availableAVO-ENH =

available in economymode

Not available / Alwaysavailable / Availablein economy mode

IPA States number of reverse gears available (14). 4 Not applicable

LAQStates highest starting gear in manual mode (16).The setting of the starting gear in manual mode is limited togears equal to or lower than this value.

6 Not applicable

LARStates highest starting gear in automatic mode (16).The choice and setting of the starting gear in automatic mode islimited to gears equal to or lower than this value.

6 Not applicable

LAP

Start gear selection dependence on ECS manual control mode.No influence =The selected start gear is not lowered duringECS control mode.During = The selected start gear is lowered during ECS controlmode.During and after = The selected start gear is lowered bothduring and after ECS control mode. Use this setting to avoid tohigh start gear before the air suspension have been raised fromthe beam stops during manual control mode.

AVO-BAS = DuringAVO-ENH = During

and after

No influence / During/ During and after

1 GJI only used at APF-ENH; the others are always included.


Communication with other control unitsSummary, components (signal summary)

T4058439

Component listComponent Description

A03 (MID 140) Central instruments

A12 (MID 136) Control unit, ABS

A13 (MID 130) Control unit, TECU (transmission electronic control unit)

A14 (MID 128) Control unit, EECU (engine electronic control unit)

A16 (MID 150) Control unit, ECS (electronically controlled suspension)

A17 (MID 144) Control unit, VECU (vehicle electronic control unit)

A21 (MID 136) Control unit, EBS (electronically-controlled brake system)

A27 (MID 216) Control unit, LCM (external lighting)

A33 (MID 220) Tachograph

A36 (MID 249) Control unit, BBM (body builder module)

A41 (MID 222) Control unit, RECU (retarder control unit)

A109 (MID 223) Control unit, GSECU (gear selection electronic control unit)


B04 Sensor, engine speed, crankshaft

B12 Sensor, tachograph/speedometer

B13-73 Sensor, wheel speed

B25 Sensor, accelerator pedal

B55-58 Sensor, air pressure in air spring bellows

B175 Sensor, load indicator

S07 Switch, engine brake

S08/S09 Switch, differential lock

S24 Retarder stalk switch

S25 Switch, cruise control

S28 Power take-off switch

S59 Position switch, brake pedal, NO

S171 Gear lever, GLU

XO5 Trailer connector, 7-pin, 24 S

Y39 Solenoid valve, VEB (Volvo engine brake)

Communication with control unit VECU, MID 144Signals / information to TECU:

The vehicle control unit parameters MG, MH and AQmust have the same values. Check the parametersettings in the VDA.

Accelerator pedal position, including kick-down. Cruise control. Retarder control. For further fault tracing see the

PC-tool, function group 5.

Power take-off control, see options instructions. Brake pedal position. Parking brake applied or not. The VECU K-factor must be the same as the

tachograph K-factor.

Vehicle weight information on leaf suspension vehicles( RADD-BR and RADD-TR), used for gear selection.

Communication with the control unit Central instruments, MID 140Signals / information from TECU:

Gear selector, positions. Gear selected. Possible gears. Driving program E/P. Time and date for diagnostics.

When using the power take-off, the driver can choosebetween N1=low split and N2=high split for differentPTO gear ratios, see the options instructions.

When the gear lever is in neutral position (N) and thebutton FOLD is pressed in, the lever can be foldedforwards, and the display shows which program setthe gearbox has.

Communication with control unit EECU, MID 128Signals / information to TECU:

Engine speed. Engine configuration Engine torque

If the engine is not running smoothly, this will adverselyaffect gear shifting.

Communication with control unit ABS/EBS, MID 136Signals / information to TECU:

Wheel speed sensor. Wheel spin information; the vehicle does not change

gear.

ABS system active, the vehicle does not change gear. Information from ESP, the vehicle does not change

gear.

If Traction Control is disengaged via the display, thevehicle does not change gear during wheel spin.

In Launch Control the gearbox can control thebrakes. For more detailed information, see Functiondescription, page 27 for Launch Control.


Communication with control unit ECS, MID 150Signals / information to TECU:

Vehicle weight. ECS control unit status. Always start in 1st gear if

the manoeuvre control unit for the air suspension is inmanual mode.

The start gear selection due to manual mode ispossible to control with parameter LAP.

Communication with control unit LCM, MID 216Signals / information to TECU:

Trailer coupled. The gearbox can select the wrong start gear and

wrong gears if the parameter ANI is not active. Thegearbox then assumes that a trailer is hitched up.

Communication with control unit BBM, MID 249Signals / information to TECU:

Power take-off (PTO) engagement. Power take-off switch control.

Gearbox, I–Shift, Generation D Design and Function

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