Diagnostic Procedure

1. Checking Faults In The Engine Management System

Check whether the CHECK ENGINE lamp is on.

Is the CHECK ENGINE lamp on?

NO
Go to Step 5

YES
Go to Step 2

2. Checking Faults In The Engine Management System

Read off and rectify any diagnostic trouble codes in the engine management system.

When repairs are complete
Go to Step 3

3. Final Check





Clear the diagnostic trouble codes in all systems.

Carry out a drive cycle:
- Drive the car at varying engine loads and engine rpm for five minutes.

Evaluate the drive cycle'.





Check that the diagnostic trouble code has not recurred

Is the function correct?

NO
Go To Step 7

YES
Go To Step 4

4. Final Check

The steps taken to rectify the fault were correct.
Diagnosis is complete

5. Checking Signals From The Engine Management System





Turn the ignition switch to the ON position.





Contact TCM.

Test value.
- Accelerator Position (Bus from TRIONIC)
- The values should be 9% when the accelerator pedal is not touched and 92% when the accelerator pedal is fully depressed.

Is the reading correct?

NO
Go to step 6

YES
Return to step 3

6. Rectifying The Lead

Repair or replace the lead between pin 39 of the transmission control module and pin 57 of the TRIONIC control module, or between pin 39 of the transmission control module and pin 52 of the Motronic control module.

When repairs are complete
Return to step 3

7. Final Check

Diagnosis for this fault code is complete.
Refer to Procedures, Before Changing A Control Module.