Code 7-4, Rear Solenoid
- Disconnect 3-pin connector from rear solenoid connector. Using a DVOM, measure resistance between Red and Black wires and between Yellow and Black wires of rear solenoid. If resistance is 1-3 ohms, go to next step. If resistance is not 1-3 ohms, replace faulty solenoid.
- Disconnect 12-pin connector from control unit. Check for continuity of Red/White wire between control unit connector and rear solenoid. If continuity exists, go to next step. If no continuity exists, repair open in Red/White wire.
- Check for continuity between Yellow/White wire of control unit connector and rear solenoid. If continuity exists, go to next step. If no continuity exists, repair open in Yellow/White wire.
- Check for continuity between Red/White wire of control unit connector and ground. If no continuity exists, go to next step. If continuity exists, repair short in Red/White wire.
- Check for continuity between Yellow/White wire of control unit connector and ground. If no continuity exists, go to next step. If continuity exists, repair short in Yellow/White wire.
- Remove and test rear fail-safe relay. See RELAY TEST under DIAGNOSIS & TESTING . Replace relay if it is defective. If relay is okay, check for continuity between Black wire and ground. If continuity exists, go to next step. If no continuity exists, check for bad ground at right front of engine compartment. If ground is okay, repair open in Black wire between fail-safe relay and ground.
- Check Blue/Black wire for continuity between rear solenoid and rear fail-safe relay. If no continuity exists, repair open in Blue/Black wire between solenoid and fail-safe relay. If continuity exists, check for loose control unit connectors. If necessary, install a known good control unit and retest.