How to Retrieve Diagnostic Trouble Codes

BMW Service Tester:

BMW MoDiC:

The contents of the defect code memory can be read out with the BMW DIAGNOSTIC SYSTEM.
Diagnostic Functions

Defect Code Storage:

If a defect occurs in the ABS or ASC+T system when the control unit is active (ignition on), this defect is stored permanently and the relevant system or the entire system is switched off. Defects at the wheel sensors can only be stored when the vehicle is driving at speeds in excess of 12 km/h. All faults which result in the ABS system switching off also cause the ASC+T system to switch off, i.e. all ABS components are monitored by the ASC+T system.

However, the ABS system is not switched off in the case of every defect in the ASC+T system. If two or more defects occur simultaneously, the one with the highest priority is stored. The lower the number of flash pulses, the higher the priority of the defect.

The ABS/ASC+T is fully operable once again if the defect no longer exists at the next start (ignition on). The defect code still remains stored in the defect code memory until it is either cleared (see "clearing defect code memory') or is overwritten by another defect code.

There are 20 different defect codes, however, only one can be stored at a time.

With the ABS/ASC+T control unit BMW No.1 159 494 (diagnostic capabilities via the diagnostic links), 3 different defect codes from a total of 22 can be stored at any one time.

Note:

In extreme driving situations (skidding) with the ASC+T system switched off, it is possible that the ABS system cuts out and the defect code 14 (valve relay) is stored. Simply clear the defect code memory in this case.

Defect Code Memory Readout:




Note: The steps to activate the flash code must be repeated if the ASC lamp remains on.

Activating the flash code

- Switch oft ignition

- Press ASC button and depress brake pedal simultaneously

- Hold ASC button and brake pedal depressed simultaneously and switch on ignition

- Keep depressed for at least 1 second and then release ASC button and brake pedal

Reading out the flash code:




The flash code is output for approx. 47 seconds irrespective of which defect code is stored.

After activation of the defect code the ASC lamp goes out for 3 seconds and then begins outputting the flash pulses at a flash frequency in a pulse/pause ratio of 1 sec/1 sec.

The number of flash pulses indicates which defect code is stored. Refer to the table of defect codes below.

Example:

2 flash pulses (BI) = Defect code 02