Engine Control Module (ECM)
The engine control module (ECM) (4/46) checks the relay for the starter motor and the ignition system. The logic for the start inhibition system is also in the engine control module (ECM). The engine control module (ECM) also transmits a command to the central electronic module (CEM) indicating when the fuel pump (FP) can be activated. The functions are activated after:
- the remote key is approved
- the steering column lock is unlocked
- the communication check has been run with the central electronic module (CEM) and the brake control module (BCM).
The engine control module (ECM) must be programmed with codes before it can work in the immobilizer system. This takes place for the first time during assembly in the factory, and subsequently takes place in the event the control module is replaced (when downloading software)
As a further safety precaution, the engine control module (ECM) reads off the serial number from the brake control module (BCM). These numbers are compared with the number programmed into the engine control module (ECM). The engine will not start if the numbers do not correspond. This means that these numbers must be programmed into the engine control module (ECM) if it or the brake control module (BCM) has been replaced. This takes place automatically when downloading software.
The engine control module (ECM) transmits the status of the engine (whether it is running or not) on the controller area network (CAN). The central electronic module (CEM) and the Driver information module (DIM) use this signal together with the signals from the brake control module (BCM) and transmission control module (TCM) to determine whether the steering column lock can be locked or not.