Diagnostic Mode and DTC Detection

Diagnostics Mode, ACC
A number of the ACC control module's outputs can be controlled "ACTIVATE" by means of the ISAT. The only condition is that the following two criteria are satisfied:
^ Battery voltage must be between 10 and 16 V.
^ Vehicle speed must be 0 km/h.

If either of these criteria is not satisfied, the ACC control module will not execute commands from the ISAT. This will also be indicated by the ISAT.

DTC Detection
On obtaining readouts of diagnostic trouble codes with the ISAT from the ACC control module, the following procedure should be followed:
1. Clear any manual programming and then test drive the car on the road.
2. Obtain readouts of the diagnostic trouble codes and write them down on a piece of paper.
3. Carry out calibration.
4. Obtain readouts of the trouble codes again and make a note of any additional diagnostic trouble codes.
5. Take remedial action in regard to the trouble codes.
6. Carry out calibration.

This procedure should be followed, since diagnostic trouble codes B2403 and B2493 can only be detected in connection with calibration. Make a habit of carrying out calibration after doing any work on the ACC system. Calibration is done to enable the control module to set the end positions of the stepping motors. The end positions no longer apply if the +30 supply is interrupted.