B1235

DTC Troubleshooting: B1235 (C and A/C)

DTC B1235 or DTC indicator C and A/C ON:

A Problem in the Air Mix Control Motor Circuit, Linkage, Door, or Motor Circuit (Driver's)

1. Clear the DTC with the HDS.

2. Turn the ignition switch to LOCK (0), and then to ON (II).

3. Do the Self-Diagnostic Function with the HDS or the climate control unit.

4. Check for DTCs.

Is DTC B1235 or C and A/C ON indicated?

YES -

Go to step 5.

NO -

Intermittent failure. Check for loose wires or poor connections on the driver's air mix control motor circuit.�

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

6. Test the driver's air mix control motor Driver's Air Mix Control Motor Test.

Is the driver's air mix control motor OK?

YES -

Go to step 7.

NO -

Replace the driver's air mix control motor Driver's Air Mix Control Motor Replacement, or repair the driver's air mix control linkage or door.�

7. Disconnect the driver's air mix control motor 7P connector.

8. Disconnect climate control unit connector A (28P).

9. Check for continuity between the following terminals of climate control unit connector A (28P) and the driver's air mix control motor 7P connector.









Is there continuity?

YES -

Go to step 10.

NO -

Repair an open in the wire(s) between the climate control unit and the driver's air mix control motor.�

10. Check for continuity between body ground and climate control unit connector A (28P) terminals No. 4 and No. 6 individually.





Is there continuity?

YES -

Repair a short to body ground in the wire(s) between the climate control unit and the driver's air mix control motor.�

NO -

Substitute a known-good climate control unit, and recheck. If the symptom/indication goes away, replace the original climate control unit Climate Control Unit Removal/Installation.�