Electronic Climate Control
DTC B1234 or DTC indicator J and AUTO: A Short in the Driver's Air Mix Control Motor Circuit1. Clear the DTC by turning the ignition switch OFF, and then ON (II).
2. Operate the climate control system in several modes.
3. Check for DTCs using the HDS or self-diagnostic.
Is DTC B1234 or J and AUTO indicated?
YES - Go to step 4.
NO - Intermittent failure.
4. Turn the ignition switch OFF.
5. Test the driver's air mix control motor.
Is the driver's air mix control motor OK?
YES - Go to step 6.
NO - Replace the driver's air mix control motor.
6. Disconnect the driver's air mix control motor 7P connector.
7. Disconnect the climate control unit 30P connector.
8. Check for continuity between body ground and the climate control unit 30P connector terminals No. 10, 11, 22, 26 and 29 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 the climate control unit 30P connector 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 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 - Substitute a known-good climate control unit, and recheck. If the symptom/indication goes away, replace the original climate control unit.