B1234

DTC Troubleshooting: B1234 (K)

DTC B1234 or DTC indicator K:

A Short in the Air Mix Control Motor Circuit (Driver's)

NOTE: If DTC B1234 is detected with HDS, it is not necessary to do step 1.

1. Check the sensor input display mode, and select "driver's air mix control motor" according to the table.

NOTE: This indication by segment lit on digital segments is assigned for 2 failure causes that it is necessary to decide which one is a true cause. If there is a failure in the sensor or motor, a value correspondent to the sensor or motor in the Sensor Input Display Mode is displayed as "Er", which serves to specify which is a true cause.

Is sensor value indicated "Er"?

YES -

Go to step 2

NO -

Go to troubleshooting DTC B1206 or DTC indicator K B1206

2. Clear the DTC with the HDS.

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

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

5. Check for DTCs.

Is DTC B1234 or K indicated?

YES -

Go to step 6.

NO -

Intermittent failure. Check for loose wires or poor connections on the driver's air mix control motor circuit

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

7. Disconnect the driver's air mix control motor 7P connector.

8. Disconnect climate control unit connector A (24P).

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





Is there continuity?

YES -

Repair a 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 10.

10. 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 a short in the wires.

NO -

Go to step 11.

11. Turn the ignition switch to ON (II), and measure the voltage between the same terminals and body ground.





Is there any voltage?

YES -

Repair a short to power in the wire(s) between the climate control unit and the driver's air mix control motor.

NO -

Go to step 12.

12. 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 Climate Control Unit Removal/Installation.

NO -

Replace the driver's air mix control motor Driver's Air Mix Control Motor Replacement.