HVAC - Without A/C

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 turn it to ON (II).

2. Do the Self-diagnostic Function with the heater control panel. How To Troubleshoot The Heating System (Without A/C)

3. Check for DTCs.

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

NO - Intermittent failure. Check for damaged wires or poor 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 heater control panel 24P connector.

8. Check for continuity between body ground and heater control panel 24P connector terminals No. 1, 13, and No. 18 individually.

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

NO - Go to step 9.






9. Check for continuity between heater control panel 24P connector terminals as follows.





Is there continuity between any of the terminals?
YES - Repair a short in the wire(s).

NO - Go to step 10.


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

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

NO - Substitute a known-good heater control panel, and recheck. If the symptom/indication goes away, replace the original heater control panel.