Reading fault codes (BMW 7 Series E32)

Reading fault codes without a fault code reader - flash codes

Bosch Motronic 1.1 and 1.2 systems

Only a limited number of emission-related flash codes can be identified by the flashing of the CHECK ENGINE warning light on the instrument panel. To determine the meaning of the codes, refer to the Flash Code Meaning Table at the end of this chapter.

Clearing fault codes without a code reader

Turn on the ignition and disconnect the negative cable from the battery for about 2 minutes.

Note: The first drawback of this method is that disconnecting the battery will erase all adaptive values in the control unit. Re-entering the relevant adaptive values into the memory requires starting a cold engine and driving for 20-30 minutes at various speeds and engine speeds. The engine should also idle for about 10 minutes. The second drawback is that the security codes in the radio system, the clock setting and some other values will be erased and will need to be restored after connecting the battery. Therefore, to erase the codes, you should use a fault code reader if possible.

Self-diagnosis using a trouble code reader

Note: Additional fault codes may be generated during certain tests. Care must be taken to ensure that the codes generated do not mislead the inspector.

Connect the trouble code reader to the self-diagnosis plug. Use the device for the following purposes, strictly following the instructions of the device manufacturers:

• reading fault codes;
• erasing fault codes;
• checking actuators (drives);
• display of databases.

Note: Most of the fault code numbers correspond to the electronic control unit pin number. For example, fault code 04 refers to pin number 4 of the control unit.

[The website served as the basis for the text: BMWMan]