Checking the engine management system (BMW 3 Series E46)

1. This work is provided for in the maintenance schedule and involves checking the control system using special test equipment. During the testing process, all fault codes are read from the on-board computer memory.

2. If the engine is running normally and no faults are expected, the system may not need to be checked, although the manufacturer strongly recommends that this check be performed.

3. If you do not have such equipment, carefully inspect the ignition, fuel injection, and emission control systems, as well as hoses and wiring, for damage. These systems are discussed in more detail in Chapters 4 and 5.