Fault Diagnosis, Torque Limitation, Input From Auto Trans

FAULT DIAGNOSIS, TORQUE LIMITATION, INPUT SIGNAL FROM AUTOMATIC TRANSMISSION

Symptom of fault
Rough gear-changes

Diagnostic procedure
1. Connect an ISAT scan tool.

- Maintain a constant engine speed of 3500 rpm.
- Select "AUT TRANSMISSION", "ACTIVATE" menu and the command "TORQUE LIMITATION" in the ISAT.

The engine speed must drop sharply and then stabilize at 3500 rpm. Repeat this process periodically for approx. 30 seconds.

- If this function works, the Trionic ECM is OK.
^ The cause of the rough gear-changes must be in the gearbox.
^ Continue fault diagnosis in the automatic transmission.
- If the function does not work, continue with step 2.





2. Connect a break out box.

The Trionic ECM must not be connected.

- Connect the test lamp between pins 1 and 13.
- Select "AUT TRANSMISSION", the "ACTIVATE" menu and the "TORQUE LIMITATION" command in the ISAT.

The test lamp must flash.

- If the test lamp flashes, continue at "Procedure before replacing ECM".
- If the test lamp does not flash, check and if necessary remedy the fault in the lead between Trionic, pin 13 and pin 13 of the transmission control module.
- If the lead is OK, continue fault diagnosis in the automatic transmission.