B1234

DTC B1234 or DTC indicator K and AUTO: A Short in the Driver's Air Mix Control Motor Circuit

1. Clear the DTC with the HDS.
2. Turn the ignition switch to LOCK (0), and then ON (II).
3. Do the self-diagnostic with the HDS or climate control unit.
4. Check for DTCs.

Is DTC B1234 or K and AUTO indicated?

YES - Go to step 5.

NO - Intermittent failure.

5. Turn the ignition switch to LOCK (0).
6. Disconnect the driver's air mix control motor 7P connector.
7. Disconnect the climate control unit 36P connector.
8. Check for continuity between body ground and the climate control unit 36P connector No. 13 and No. 21 terminals 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 - Go to step 9.

9. Check for continuity between the climate control unit 36P connector No. 13 and No. 21 terminals.






Is there continuity?

YES - Repair the short in the wires.

NO - Go to step 10.

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






Is there battery voltage?

YES - Repair short to power in the wire(s) between the climate control unit and the driver's air mix control motor. This short may also damage the climate control unit. Repair the short to power before replacing the climate control unit.

NO - Go to step 11.

11. Test the driver's air mix control motor.

Is the driver's air mix control motor OK?

YES - Check the driver's air mix control motor operation with the original climate control unit. If the motor operation is no good, substitute a known-good climate control unit, and recheck. If the symptom/indication goes away and the driver's air mix control motor runs, replace the original climate control unit.

NO - Replace the driver's air mix control motor.