B1237

DTC Troubleshooting: B1237 (N)

DTC B1237 or DTC indicator N:

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

1. Clear the DTC with the HDS.

2. Operate the climate control system in several modes.

3. Check for DTCs using the HDS or the self-diagnostic function.

Is DTC B1237 or N indicated?

YES -

Go to step 4.

NO -

Intermittent failure. Check for loose wires or poor connections on the passenger's air mix control motor circuit.�

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

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

6. Disconnect the climate control unit 30P connector.

7. Check for continuity between body ground and climate control unit 30P connector terminals No. 5 and No. 23 individually.





Is there continuity?

YES -

Repair a short to body ground in the wires between the climate control unit and the passenger's air mix control motor.�

NO -

Go to step 8.

8. Check for continuity between climate control unit 30P connector terminals No. 5 and No. 22.





Is there continuity?

YES -

Repair a short in the wires between the climate control unit and the passenger's air mix control motor.�

NO -

Go to step 10.

9. Turn the ignition switch to ON (II)

10. Measure the voltage between body ground and climate control unit 30P connector terminals No. 5 and No. 23 individually.





Is there voltage?

YES -

Repair a short to power in the wire(s) between the climate control unit and the passenger's air mix control motor. This short may also damage the climate control unit. Repair the short to power before replacing the climate control unit.�

NO -

Go to step 11.

11. Test the passenger's air mix control motor Passenger's Air Mix Control Motor Test (With Climate Control).

Is the passenger's air mix control motor OK?

YES -

Substitute a known-good climate control unit Climate Control Unit Removal/Installation, and recheck. If the symptom/indication goes away, replace the original climate control unit Climate Control Unit Removal/Installation.�

NO -

Replace the passenger's air mix control motor Passenger's Air Mix Control Motor Replacement (With Climate Control).�