Self-diagnosis system and fault codes

If a malfunction occurs in the ignition and fuel injection system while driving, the defect is stored in the control unit in the form of a code. At the same time, the control unit switches to the emergency program so that you can continue driving. With the engine off, the defect can be recalled using the BMW Service Tester.

Short circuits, breaks, excess enrichment values or incomprehensible functioning are stored as defects. In this case, a stored defect may be a failure of the element, the corresponding wires or the control unit. In addition, the frequency of occurrence of a stored defect can be derived from the memory.

Attention: If the battery is disconnected or the ECU connector is disconnected, the data in the memory is erased.

Up to 5 defects can be stored in memory. With a greater number of defects that have occurred, one of the stored defects is erased.