Diagnostic device memory (BMW 7 Series E32)

The electronics of the control unit detect faults in the injection system and ignition system, such as faulty sensors, disconnected plugs and loose contacts. These faults are stored in the diagnostic device memory as codes immediately after their first occurrence. At the same time, the engine warning light on the instrument panel lights up, indicating that a fault has been stored in the memory. If the fault occurs only once, for example due to a loose contact, the warning light goes out, but the fault code remains stored in the memory. In addition, the memory contains information about the frequency of occurrence of the fault. In a specialist workshop, using a diagnostic device connected to the diagnostic plug (located on the right side of the engine compartment), read stored fault codes and erase them.

If the engine or injection system is not working properly, it is recommended to first interrogate the diagnostic device memory in a workshop with special diagnostic equipment.

All versions of the DME system have a fail-safe function: if a sensor fails, the control unit uses the backup (average) values supplied by the corresponding sensor. If the air flow meter fails, the control unit uses the throttle position data and engine speed as the base values for fuel dosing. This regulation is activated automatically and independently of the driver. The journey can continue, and engine performance often changes only slightly. However, faults are recognized by the control unit and stored in the memory.

Caution: When the battery cables are disconnected or the control unit plug is disconnected, all fault codes are cleared.

[The original source of the article is on the website «www.bmwman.ru»]