HVAC - With A/C

HVAC DTC Troubleshooting: 1

DTC indicator 1: An Open in the Air Mix Control Motor Circuit

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 1 indicated?
YES - Go to step 4.

NO - Intermittent failure. Check for loose wires or poor connections on the air mix control motor circuit.


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

5. Test the air mix control motor. Air Mix Control Motor Test

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

NO - Replace the air mix control motor. Air Mix Control Motor Replacement


6. Disconnect the air mix control motor 7P connector.

7. Disconnect the HVAC control unit 24P connector.

8. Check for continuity between the following terminals of the HVAC control unit 24P connector and the air mix control motor 7P connector.





Is there continuity?
YES - Check for loose wires or poor connections at the HVAC control unit 24P connector and at the air mix control motor 7P connector. If the connections are good, substitute a known-good HVAC control unit Service and Repair and recheck. If the symptom/indication goes away, replace the original HVAC control unit.

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