Technical Definition:
Engine Control Module (ECM) / Powertrain Control Module (PCM) Power Relay Sensore Circuit / Open
Trouble Code: P0688
Address: 0x0688
System: Powertrain
Subsystem: Computer and Auxiliary Output Circuits
Address: 0x0688
System: Powertrain
Subsystem: Computer and Auxiliary Output Circuits
Technical Description:
Possible Causes:
Possible Symptoms:
Electronic Control Module Power Relay Sense Circuit/Open
Possible Solutions:
OBD-II Trouble Code Type:
Diagnostic Step:
Tech Notes:
– Weak battery – Low voltage while cranking
– Faulty Engine Control Module (ECM) relay
– Blown ECM fuse
– Faulty ECM
– ECM harness is open or shorted
– ECM circuit poor electrical connection