Possible causes

– Faulty Engine Control Module (ECM)
– ECM harness is open or shorted
– ECM circuit poor electrical connection
– ECM Programming

Tech notes

Check the ECM fuse, if fuse is OK try erasing the code first and if the code comes back you may have to reprogram or replaced the ECM.

When is the code detected?

Indicates the ECM has experienced an internal memory fault.

Symptoms

– Engine Light ON (or Service Engine Soon Warning Light)

P0657 Description

The ECM continuously monitors its internal memory status, internal circuits, and output signals 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.

P0657 Information for specific makes

P0657 ACURA
P0657 CHRYSLER
P0657 DODGE
P0657 FORD
P0657 HONDA
P0657 JEEP
P0657 LEXUS
P0657 MITSUBISHI
P0657 TOYOTA
P0657 VOLKSWAGEN
P0657 SCION