DTC Troubleshooting: 1

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

1.Clear the DTC.

2.Turn the ignition switch OFF, and then ON (II).

3.Do the self-diagnostic with the HVAC control unit .

4.Check for DTCs.

Is DTC 1 indicated?


YES - Go to 5.


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


5.Turn the ignition switch OFF.

6.Test the air mix control motor.

Is the air mix control motor OK?


YES - Go to 7.


NO - Replace the air mix control motor.n


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

8.Disconnect the HVAC control unit 24P connector.

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

24P: 7P: 
No. 1 No. 5 
No. 13 No. 7 
No. 18 No. 3 
No. 19 No. 2 
No. 20 No. 1 

 

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 and recheck. If the symptom/indication goes away, replace the original  HVAC control unit.n


NO - Repair any open in the wires between the HVAC control unit and the air mix control motor.n