B1235

DTC B1235 or DTC indicator L and AUTO: A Problem in the Driver's Air Mix Control Linkage, Door, or Motor

1. Clear the DTC with the HDS.
2. Turn the ignition switch OFF, and then ON (II).
3. Do the self-diagnostic with the HDS or climate control unit.
4. Check for DTCs.

Is DTC B1235 or L and AUTO indicated?

YES - Go to step 5.

NO - Intermittent failure.

5. Turn the ignition switch OFF.
6. Test the driver's air mix control motor.

Is the driver's air mix control motor OK?

YES - Go to step 6.

NO - Replace the driver's air mix control motor, 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 (24P).




9. Check for continuity between the terminals of the climate control unit connector A (24P) and the driver's air mix control motor 7P connector.

Is there continuity?

YES - Go to step 9.

NO - Repair 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 (24P) terminals No. 9 and No. 10 individually.

Is there continuity?

YES - Repair 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.