DTC ECM-720A

Condition







The engine control module (ECM) interprets the following as faults: If the engine control module (ECM) does not communicate with the immobilizer-function (in the central electronic module (CEM)) within 2 seconds of the ignition being switched on. If there is no communication. If the +15-supply between the ignition switch and the engine control module (ECM) is switched on and off while driving. If there is a "faulty signal". If a "faulty VIN code" is sent from the immobilizer function. Diagnostic trouble code ECM-720A is stored if any of these faults occurs.

Substitute value
None.

Possible source

Faulty communication:
- the ignition has been switched on and off more than three times while driving.

No communication:
- faulty key (transponder read off or not programmed)
- open-circuit or interference in the communication cable between the central electronic module (CEM) and the engine control module (ECM)
- defective central electronic module (CEM)
- defective central electronic module (CEM).

Incorrect VIN code:
- defective central electronic module (CEM)
- defective central electronic module (CEM)
- defective engine control module (ECM)
- faulty engine control module (ECM).

Fault symptom[s]
- the engine starts but stops immediately.