P0690 ISUZU Engine Controls Ignition Relay Feedback Circuit High Voltage

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 Tech description Check all the ECM fuses, if the fuses are OK try replacing the ECM relay. Symptoms – Engine Light ON (or…