P0689 – Electronic Control Module Power Relay Sense Circuit Low
P0689 Possible Symptoms
Engine Light ON (or Service Engine Soon Warning Light)
P0689 Possible Causes
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
The Engine Control Module (ECM) monitors the power inputs. The ECM sets the OBDII code when the ECM remains powered up after the ignition switch has been turned OFF.