P0604 BMW – ECM Self Check Fault

P0604 BMW Possible Symptoms

Engine Light ON (or Service Engine Soon Warning Light),Engine may not start

P0604 BMW Possible Causes

Loose or poor battery terminal connection,Low battery charge,ECM power supply circuit is open or shorted,ECM Programing,Faulty ECM

P0604 BMW Description

The ECM continuously monitors its own internal memory status, internal circuits, and output signals transmitted to the throttle actuator. This self-check insures that the ECM is functioning properly. If any malfunction is detected, the ECM will set the code and illuminate the engine light.