B and A/C

DTC Troubleshooting: B1234 (B and A/C)

DTC B1234 or DTC indicator B and A/C:

A Short in the Air Mix Control Motor Circuit

1. Clear the DTCs with the HDS.

2. Turn the ignition switch to LOCK (0) and then back to ON (II).

3. Do the self-diagnostic function with the HDS or the climate control unit.

4. Check for DTCs.

Is DTC B1234 or B and A/C indicated?

YES -

Go to step 5.

NO -

Intermittent failure, check for loose wires or poor connections in the air mix control motor circuit.

5. Turn the ignition switch to LOCK (0).

6. Test the air mix control motor Air Mix Control Motor Test.

Is the air mix control motor OK?

YES -

Go to step 7.

NO -

Replace the air mix control motor Air Mix Control Motor Replacement.

7. Disconnect the air mix control motor 7P connector and humidity/in-car temperature sensor 4P connector.

8. Disconnect the climate control unit 36P connector.

9. Check for continuity between body ground and climate control unit 36P connector terminals No. 3 and No. 5 individually.





Is there continuity?

YES -

Repair a short to body ground in the wires between the climate control unit and the air mix control motor.

NO -

Go to step 10.

10. Check for continuity between climate control unit 36P connector terminals No. 3 and No. 5.





Is there continuity?

YES -

Repair a short in the wires between the climate control unit and the air mix control motor.

NO -

Go to step 11.

11. Turn the ignition switch to ON (II).

12. Measure the voltage between body ground and climate control unit 36P connector terminals No. 3 and No. 5 individually.





Is there any voltage?

YES -

Repair a short to power in the wires between the climate control unit and the 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 -

Substitute a known-good climate control unit, and recheck. If the symptom/indication goes away, replace the original climate control unit Climate Control Unit Removal/Installation.