Climate Control

DTC Troubleshooting: B1239 (A)

DTC B1239 or DTC indicator A:

An Open or Short in the Front Mode Control Motor Circuit

1. Clear the DTC by turning the ignition switch to LOCK (0), and then turn to ON (II).

2. Operate the climate control system in several modes.

3. Check for DTCs using the HDS How to Troubleshoot the Climate Control System or self-diagnostic function How to Troubleshoot the Climate Control System.

Is DTC B1239 or A indicated?

YES -

Go to step 4.

NO -

Intermittent failure, check for loose wires or poor connections on the front mode control motor circuit.�

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

5. Test the front mode control motor Front Mode Control Motor Test.

Is the front mode control motor OK?

YES -

Go to step 6.

NO -

Replace the front mode control motor Front Mode Control Motor Replacement.�

6. Disconnect the front mode control motor 7P connector.

7. Disconnect the front climate control unit 30P connector.

8. Check for continuity between the following terminals of front climate control unit 30P connector and the front mode control motor 7P connector.









Is there continuity?

YES -

Go to step 9.

NO -

Repair an open in the wire(s) between the front climate control unit and the front mode control motor.�

9. Check for continuity between body ground and front climate control unit 30P connector terminals No. 2, 3, 4, 5, and 29 individually.





Is there continuity?

YES -

Repair a short to body ground in the wire(s) between the front climate control unit and the front mode control motor.�

NO -

Go to step 10.

10. Check for continuity between terminals of front climate control unit 30P connector as follows.





Is there continuity between any of the terminals?

YES -

Repair a short in the wires.�

NO -

Go to step 11.

11. Turn the ignition switch to ON (II), and measure the same terminals for voltage to body ground.





Is there any voltage?

YES -

Repair a short to power in the wire(s) between the front climate control unit and the mode control motor. This short may also damage the front climate control unit. Repair the short to power before replacing the front climate control unit.�

NO -

Check for loose wire or poor connections at the front climate control unit 30P connector and at the mode control motor 7P connector. If the connections are good, substitute a known-good front climate control unit, and recheck. If the symptom/indication goes away, replace the original front climate control unit Front Climate Control Unit Removal/Installation.�