B1234

DTC Troubleshooting: B1234 or Indicator K and AUTO

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 to ON (II).

3. Do the self-diagnostic with the HDS Initial Inspection and Diagnostic Overview or climate control unit. Initial Inspection and Diagnostic Overview

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 climate control unit connector A (24P).

8. Check for continuity between body ground and climate control unit connector A (24P) No. 5 and No. 16 terminals individually.

Is there continuity?
YES - Repair any 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 terminals of climate control unit connector A (24P) 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 to ON (II), and check the same terminals for voltage.

Is there any voltage?
YES - Repair short to power in the wire(s) between the climate control unit and the driver's air mix control motor.

NO - Go to step 11.






11. Test the driver's air mix control motor. Driver's Air Mix Control Motor Test

Is the driver's air mix control motor OK?
YES - Check for loose wire or poor connections at climate control unit connector A (24P) and at the driver's air mix control motor 7P connector. If the connections are good, check the driver's air mix control motor operation with the original climate control unit. If the motor is not 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. Driver's Air Mix Control Motor Replacement