Troubleshooting with diagnostic codes

3500B engines

System over view Electronic system consist of :- -ECM -Wiring harness -Switches -Sensors -Electronic unit injector

Electronic controls ECM:- supplies signal to electronic unit

injectors control engine operation consists of : - hardware and software govern engine speed

Fuel injection ECM controls timing, duration of

injectors (105v) Timing Quantity of fuel Desired engine RPM

Injection timing depends on :-

Engine RPM Load Other operational factors

ECM sends signal at the desired time, limits engine power during cold mode operation, modifies

injection time and cuts out cylinders .This increase startability

and reduce warming time

Self diagnostic ECM detects problem, generate a

code and an alarm. Diagnostic Events These have two states:- Active Logged

Electronic service tools Designed to perform the

following functions:- Obtain data from the engine Display diagnostic codes Perform sensor calibrations Read and change programmable

parameters

ET Display:- Sensor values Diagnostic codes Engine configuration

ET Perform:- Diagnostic tests Sensor calibration Flash downloading Set programmable

parameters

Troubleshooting with diagnostic codes

Diagnostic codes :- Alert that a problem exists Indicate the nature of the problem Consists of :-

MID CID FMI

Engine programmed to perform the following actions:-

Engine warning Engine derate Engine shutdown

electronic service tool used to activate these features

4.8V

4.2V

2.8V

0.2V

107 ْ c

63 ْْc

Sensor diagnostic generatedElectronic problem

Logged event ,warning, derate and shut down occur if applicable

Engine is too hot but there is not an electronic problem

Warm mode tempRange from 20-106 ْc

Sensor diag. generatedelect. problem

Cold mode temp-40 – 20 ْc

Normal engine

temp range