M and Auto

DTC Troubleshooting: B1236 or Indicator M and AUTO

DTC B1236 or DTC indicator M and AUTO:An Open in the Passenger's Air Mix Control Motor Circuit

1. Start the engine.

2. Turn on the A/C, then set the passenger's climate control switch to max hot.

3. Turn the ignition switch to LOCK (0).

4. Clear the DTC with the HDS.

5. Turn the ignition switch to LOCK (0), and then to ON (II).

6. Do the self-diagnostic with the HDS Initial Inspection and Diagnostic Overview or climate control unit. Initial Inspection and Diagnostic Overview

7. Check for DTCs.

Is DTC B1236 or M and AUTO indicated?
YES - Go to step 8.

NO - Intermittent failure.


8. Turn the ignition switch to LOCK (0).

9. Disconnect the passenger's air mix control motor 7P connector.

10. Disconnect climate control unit connector A (24P).

11. Check for continuity between the following terminals of climate control unit connector A (24P) and the passenger's air mix control motor 7P connector.





Is there continuity?
YES - Go to step 12.

NO - Repair open in the wire(s) between the climate control unit and the passenger's air mix control motor.






12. Test the passenger's air mix control motor. Passenger's Air Mix Control Motor Test

Is the passenger's air mix control motor OK?
YES - Check for loose wire or poor connections at climate control unit connector A (24P) and at the passenger's air mix control motor 7P connector. If the connections are good, substitute a known-good climate control unit, and recheck. If the symptom/indication goes away, replace the original climate control unit.

NO - Replace the passenger's air mix control motor. Passenger's Air Mix Control Motor Replacement