DTC J and AUTO
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 to LOCK (0), and then turn to 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 to LOCK (0).
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 front climate control unit 30P connector.
8. Check for continuity between body ground and the front climate control unit 30P connector No. 22, 26, and 29 terminals individually.
Is there continuity?
YES - Repair short to body ground in the wire(s) between the front 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 front 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 to ON (II), and measure the same terminals for voltage to body ground.
Is there any voltage?
YES - Repair short to power in the wire(s) between the front climate control unit and the driver's air mix control motor. This short may also damage the front climate control unit. Repair the short to power before replacing the front climate control unit.
NO - Substitute a known-good front climate control unit, and recheck. If the symptom/indication goes away, replace the original front climate control unit.