HVAC

HVAC DTC Troubleshooting: 9

DTC 9:

A Problem in the Air Mix Control Linkage, Door, or Motor

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 Initial Inspection and Diagnostic Overview.

3. Check for DTCs.

Is DTC 9 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, or repair the air mix control linkage or door.�

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

7. Disconnect the heater control panel 30P connector.

8. Check for continuity between the following terminals of the heater control panel 30P connector and the air mix control motor 7P connector.









Is there continuity?

YES -

Go to step 9.

NO -

Repair an open in the wire(s) between the heater control panel and the air mix control motor.�

9. Check for continuity between body ground and heater control panel 30P connector terminals No. 1 and No. 2 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 -

Substitute a known-good heater control panel, and recheck. If the symptom/indication goes away, replace the original heater control panel Service and Repair.�