P1612 INFINITI Chain of ECM-IMMU

Possible causes
– Faulty or not programmed ignition key
– Faulty IMMU
– Faulty Engine Control Module (ECM)
Tech notes
This code is usually triggered when a not registered or damaged key is used to start the engine. When the starting operation is carried out five or more times consecutively with the same unregistered key, the system will lock.

If the problem occurs try disconnecting the car battery for about 30 minutes and then try starting the engine with a known registered key. If the problem persist you have to have the dealer erase the code and reprogram the keys again.

When is the code detected?
Communication impossible between ECM and IMMU (In rare cases,