Climate Control

DTC Troubleshooting: B1221 (I)

DTC B1221 or DTC indicator I:

An Open in the Rear 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 B1221 or I indicated?

YES -

Go to step 4.

NO -

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

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

5. Test the rear mode control motor Rear Mode Control Motor Test.

Is the rear mode control motor OK?

YES -

Go to step 6.

NO -

Replace the rear mode control motor Rear Mode Control Motor Replacement.�

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

7. Disconnect the rear climate control unit 22P connector.

8. Check for continuity between the following terminals of the rear climate control unit 22P connector and the rear mode control motor 7P connector.









Is there continuity?

YES -

Check for loose wire or poor connections at the rear climate control unit 22P connector and at the rear mode control motor 7P connector. If the connections are good, substitute a known-good rear climate control unit, and recheck. If the symptom/indication goes away, replace the original rear climate control unit Rear Climate Control Unit Removal/Installation.�

NO -

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