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
Symptoms
– Engine Light ON (or Service Engine Soon Warning Light)
P0657 CHRYSLER OBD Code Description
The Transmission Control Moduel (TCM) has detected a voltage supply fault to the hydraulic control unit