Heating and Air Conditioning

DTC B1234 or DTC indicator 2: A Short 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 B1234 or 2 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 - 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 body ground and A/C control panel connector A (22P) terminals No. 3, 7, 13, 21, and 22 individually.

Is there continuity?

YES - Repair any short to body ground in the wire(s) between the A/C control panel and the air mix control motor.

NO - Go to step 9.




9. Check for continuity between the terminals of A/C control panel connector A (22P) as follows.

Is there continuity between any of the terminals?

YES - Repair the short in the wires.

NO - Go to step 10.




10. Turn the ignition switch ON (II), and check the same terminals for voltage to body ground.

Is there any voltage?

YES - Repair any short to power in the wire(s) between the A/C control panel and the air mix control motor. This short may also damage the A/C control panel. Repair the short to power before replacing the A/C control panel.

NO - Substitute a known-good A/C control panel, and recheck. If the symptom/indication goes away, replace the original A/C control panel.