B1239
DTC B1239 or DTC indicator L: A Short or Open in the Mode Control Motor Circuit1. Clear the DTC.
2. Turn the ignition switch OFF, and then ON.
3. Operate the climate control system in several modes.
4. Check the DTCs.
Is DTC B1239 or K indicated?
YES - Go to step 5.
NO - Intermittent failure, check for loose wires or poor connections on the mode control motor circuit.
5. Test the mode control motor.
Is the mode control motor OK?
YES - Go to step 6.
NO - Replace the mode control motor.
6. Disconnect the mode control motor 7P connector.
7. Disconnect audio-HVAC display panel connector A (22P).
8. Check for continuity between body ground and audio-HVAC display panel connector A (22P) terminals No. 6, 7 , 15, 16, 17, 18 and 19 individually.
Is there continuity?
YES - Repair any short to body ground in the wire(s) between the audio-HVAC display panel and the mode control motor.
NO - Go to step 9.
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 mode control motor. This short may also damage the climate control unit. Repair the short to power before replacing the audio-HVAC display panel.
NO - Go to step 10.
10. Turn the ignition switch OFF, and check for continuity between following terminals of audio-HVAC display panel connector A (22P) and the mode control motor 7P connector.
Is there continuity?
YES - Check for loose wire or poor connections at audio-HVAC display panel connector A (22P) and at the mode control motor 7P connector. If the connections are good, substitute a known-good audio-HVAC display panel, and recheck. If the symptom/indication goes away, replace the original audio-HVAC display panel.
NO - Repair any open in the wire(s) between the climate control unit and the mode control motor.