How to Clear Diagnostic Trouble Codes

Clearing Defect Code Memory:

There are three possible ways of clearing the defect code memory:

Within 3 seconds after the end of the flash code output (after 47 seconds) when the ASC lamp lights permanently once again, press the ASC button for at least 1 second.

Disconnect vehicle battery (Attention! Defect code memories of other systems may be cleared).

Disconnect control unit (Attention! Ignition must be switched off). In the case of ABS/ASC+T control unit with BMW No.1 159 494 (diagnostic capabilities via the diagnostic links), the contents of the defect code memory can be cleared with the BMW DIAGNOSTIC SYSTEM. The contents of the defect code memory are not deleted If the control unit is disconnected.

Troubleshooting Procedure:

- Check system for mechanical and hydraulic defects (refer to Repair Instructions Group 34)
- Read out defect code memory via flash code

Note:

If the defect code cannot be read out, then continue troubleshooting as described under point "Other system defects".

- Note down number of flash pulses
- In order to exclude the possibility of any counting errors, read out the defect code memory once again
- Clear defect code memory
- Perform troubleshooting with schematic
- Rectify defect
- Perform test run

Note:

During the test run, the car should be driven for at least 20 sec at a speed in excess of 30 km/h or for at least 3 seconds at a speed above 50 km/h.

- If defect code is stored once again, repeat procedure until no defect code is stored.

Simulating ASC Control Mode:

- Raise vehicle on floor jack (all wheels must turn freely)
- Set automatic selector lever to "neutral (N)"
- Start engine
- Set engine speed by means of accelerator pedal or adapter EML No. 12.7010, to Approx. 2000 rpm
- Quickly accelerate rear left or rear right.wheel by hand in forward direction

Reaction: Braking of the turned wheel must be felt.