DTC Troubleshooting: B1234 (J)

DTC indicator J or DTC B1234: A Short in the Driver's Air Mix Control Motor Circuit Clear the DTC. Turn the ignition switch OFF, and then ON. Operate the climate control system is several modes. Check the DTCs. Is DTC J or B1234 indicated?
YES | - | Go to Step 5 .
NO | - | Intermittent failure.■
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.■
Disconnect the driver's air mix control motor 7P connector. Disconnect climate control unit connector A (22P). Check for continuity between body ground and climate control unit connector A (22P) terminals No. 1, 8, 9, 15, and 20 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 .

Turn the ignition switch ON (II), and check the same terminals for voltage. 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 also damages the climate control unit. Repair the short to power before replacing the climate contorol unit.■
NO | - | Go to Step 10 .
Perform the A/C communication in the Self-Diagnostic Function to obtain the IS-BUS communication varification status. Is the communication OK?
YES | - | Substitute a known-good climate control unit and printed circuit board, and recheck. If the symptom/indication goes away, replace the original climate control unit and printed circuit board.■
NO | - | Substitute a known-good climate control unit, and recheck. If the symptom/indication goes away, replace the original climate control unit .■