Possible causes
– Faulty Engine Control Module (ECM)
– ECM harness is open or shorted
– ECM circuit poor electrical connection
– ECM Programming
– ECM harness is open or shorted
– ECM circuit poor electrical connection
– ECM Programming
Tech description
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 obd code mean?
Indicates the Engine Control Module (ECM) has experienced an internal memory fault.
Symptoms
– Engine Light ON (or Service Engine Soon Warning Light)
P0657 LEXUS OBD Code Description
The Engine Control Module (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.