Heating and Air Conditioning

DTC B1233 or DTC indicator 1: An Open in the Air Mix Control Motor Circuit

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 B1233 or 1 indicated?

YES - Go to step 4.

NO - Intermittent failure, check for loose wires or poor connections on the air mix control motor circuit.

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

Is the air mix control motor OK?

YES - Go to step 6.

NO - Replace the air mix control motor.

6. Disconnect the air mix control motor 7P connector.
7. Disconnect A/C control panel connector A (22P).




8. Check for continuity between the above terminals of A/C control panel connector A (22P) and the air mix control motor 7P connector.

Is there continuity?

YES - Check for loose wire or poor connections at A/C control panel connector A (22P) and at the air mix control motor 7P connector. If the connections are good, substitute a known-good A/C control panel and recheck. If the symptom/indication goes away, replace the original A/C control panel.

NO - Repair any open in the wire(s) between the A/C control panel and the air mix control motor.