HVAC - With A/C

HVAC DTC Troubleshooting: 5

DTC indicator 5: A Problem in the Mode Control Linkage, Doors, or Motor

1. Turn the ignition switch to LOCK (0), and then turn it to ON (II).

2. Do the self-diagnostic with the HVAC control unit. How To Troubleshoot The Heating and A/C Systems (With A/C)

3. Check for DTCs.

Is DTC 5 indicated?
YES - Go to step 4.

NO - Intermittent failure. Check for damaged wires or poor connections in the mode control motor circuit.


4. Turn the ignition switch to LOCK (0).

5. Test the mode control motor. Mode Control Motor Test

Is the mode control motor OK?
YES - Go to step 6.

NO - Replace the mode control motor, Mode Control Motor Replacement or repair the mode control linkage or doors.


6. Check for continuity between the following terminals of the HVAC control unit 24P connector and the mode control motor 7P connector.





Is there continuity?
YES - Go to step 7.

NO - Repair open in the wire(s) between the HVAC control unit and the mode control motor.






7. Check for continuity between body ground and the HVAC control unit 24P connector terminals No. 14 and No. 15 individually.

Is there continuity?
YES - Repair short to body ground in the wire(s) between the HVAC control unit and the mode control motor.

NO - Substitute a known-good HVAC control unit Service and Repair, and recheck. If the symptom/indication goes away, replace the original HVAC control unit.