Faulty Engine Controls Ignition Relay
Engine Controls Ignition Relay harness is open or shorted
Engine Controls Ignition Relay circuit poor electrical connection
Faulty Engine Control Module (ECM)
Engine Light ON (or Service Engine Soon Warning Light)
There are 3 ignition voltage circuits supplied to the Engine Control Module (ECM). Two are supplied by the engine controls ignition relay, and the other is supplied by the ignition main relay. The ECM monitors and compares the ignition voltage supplied by the 2 relays. The Diagnostic Trouble Code (DTC) will be set when the ECM detects the engine controls ignition relay feedback circuit 2 is less than 5 V.