Verifying Repairs

Verifying repairs

General
After carrying out repairs it may be necessary to check that the fault really has been remedied. One way of doing this is to check that the engine control module (ECM) has carried out a self diagnostic for the function / component that has been repaired, and that the diagnostic trouble code (DTC) has not recurred.
Verifying repairs is only intended as an aid if uncertain whether the fault persists or not. If an obvious fault is detected during fault-tracing it is not necessary to verify the repair.

Carrying out a TRIP
Check all diagnostic functions as follows.
To complete a TRIP as fast as possible follow a special driving schedule.
- If the engine control module (ECM) has been without power the engine must be started a few times before the test is carried out
- If the vehicle has been without power and misfire-related diagnostic trouble codes (DTCs) are being verified, a flywheel adaptation must be carried out before verification. See Misfire diagnostics under Design and Function.
- The test must take place on a road with little traffic where it is possible to drive slowly and stop at the side of the road
- The air conditioning (A/C) can be on when the engine is running at part load but must be switched off before the engine is run at idle speed
- For all diagnostics to be carried out, the engine coolant temperature (ECT) should not be above 25° C when the engine is started before the test
- Ensure that there are no diagnostic trouble codes (DTCs) stored in the system before carrying out verification
- Start the engine. Drive according to driving schedule.

Driving schedule:
- Start the engine
- shift gear selector to drive
- accelerate gently to 1500-2000 rpm
- drive for 5 minutes at 1500-2000 rpm
- run the engine at idle speed for 70 seconds
- drive engaged, air conditioning (A/C) off
- drive for 6 minutes at 1500-2000 rpm
- run the engine at idle speed for 40 seconds
- drive engaged
- air conditioning (A/C) off
- drive for 5 minutes at 1500-2000 rpm
- run the engine at idle speed for 50 seconds
- drive for 5 minutes at 1500-2000 rpm
- Engine brake from 4000 rpm to approximately 1300 rpm a few times.

Note! Do not use the accelerator pedal (AP) during engine braking.