Manufacturer Code Charts: 2

HVAC DTC Troubleshooting: 2

DTC indicator 2: A Short in the Air Mix Control Motor Circuit

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

2. Do the self-diagnostic function with the HVAC control unit. How to Troubleshoot the Heating and A/C Systems

3. Check for DTCs.

Is DTC 2 indicated?
YES - Go to step 4.

NO - Intermittent failure. Check for damaged wires or connections in 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 body ground and the HVAC control unit 24P connector No. 13 and No. 17 terminals individually.

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

NO - Go to step 9.






9. Check for continuity between the HVAC control unit 24P connector No. 13 and No. 17 terminals.

Is there continuity?
YES - Repair short in the wires.

NO - Go to step 10.






10. Turn the ignition switch to ON (II), and check the same terminals for voltage between each terminal and body ground.

Is there any voltage?
YES - Repair short to power in the wire(s) between the HVAC control unit and the air mix control motor. This short may also damage HVAC control unit. Repair short to power before replacing the HVAC control unit.

NO - Substitute a known-good HVAC control unit and recheck. If the symptom/indication goes away, and the air mix control motor runs, replace the original HVAC control unit.