Heating and Air Conditioning

DTC B1235 or DTC indicator 3: A Problem in the Air Mix Control Linkage, Door, or Motor

1. Clear the DTC by turning the ignition switch OFF, and then ON (II).
2. Operate the A/C control system in several modes.
3. Check for DTCs using the HDS or self-diagnostic.

Is DTC B1235 or 3 indicated?

YES - Go to step 4.

NO - Intermittent failure.

4. Turn the ignition switch OFF.
5. Test the air mix control motor.

Is the air mix control motor OK?

YES - Substitute a known-good A/C control panel, and recheck. If the symptom/indication goes away, replace the original A/C control panel.

NO - Replace the air mix control motor, or repair the air mix control linkage or door.