Operation CHARM: Car repair manuals for everyone.

B1237

DTC B1237: A Short in the Passenger's Air Mix Control Motor Circuit

1. Clear the DTC.
2. Turn the ignition switch OFF, and then ON.
3. Operate the climate control system is several modes.
4. Check the DTCs.

Is DTC P or B1237 indicated?

YES - Go to step 5.

NO - Intermittent failure.

5. Test the passenger's air mix control motor.

Is the passenger's air mix control motor OK ?

YES - Go to step 6.

NO - Replace the passenger's air mix control motor.

6. Disconnect the passenger's air mix 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.2, 10, 15, 20 and 22 individually.

Is there continuity?

YES - Repair any short to body ground in the wire(s) between the audio-HVAC display panel and the passenger's air mix 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 audio-HVAC display panel and the passenger's air mix control motor. This short also may damage the audio-HVAC display panel. Repair the short to power before replacing the audio-HVAC display panel.

NO - Check for loose wire or poor connections at audio-HVAC display panel connector A (22P) and at the evaporator temperature sensor 2P 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.