P0685 ISUZU Engine Controls Ignition Relay Control Circuit

Possible causes

– Faulty Engine Control Module (ECM) power relay
– ECM power relay harness is open or shorted
– ECM power relay circuit poor electrical connection
– Faulty (ECM)

Tech description

Check all the ECM fuses, if the fuses are OK try replacing the ECM relay.

Symptoms

– Engine Light ON (or Service Engine Soon Warning Light)