N and Auto

DTC Troubleshooting: B1237 or Indicator N and AUTO

DTC B1237 or DTC indicator N and AUTO:A Short in the Passenger's Air Mix Control Motor Circuit

1. Clear the DTC with the HDS.

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

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

4. Check for DTCs.

Is DTC B1237 or N and AUTO indicated?
YES - Go to step 5.

NO - Intermittent failure.


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

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

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

8. Check for continuity between body ground and climate control unit connector A (24P) No. 5 and No. 15 terminals individually.

Is there continuity?
YES - Repair short to body ground in the wire(s) between the climate control unit and the passenger's air mix control motor.

NO - Go to step 9.






9. Check for continuity between the terminals of climate control unit connector A (24P) 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 check the same terminals for voltage.

Is there any voltage?
YES - Repair short to power in the wire(s) between the climate control unit and the passenger's air mix control motor.

NO - Go to step 11.






11. 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, check the passenger's air mix control motor operation with the original climate control unit. If the motor is not good, substitute a known-good climate control unit, and recheck. If the symptom/indication goes away and the passenger's air mix control motor runs, replace the original climate control unit.

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