B1238
DTC B1238 or DTC indicator N: A Problem in the Passenger's Air Mix Control Linkage, Door, or Motor1. Clear the DTC with the HDS.
2. Operate the climate control system in several modes.
3. Check for DTCs using the HDS or self-diagnostic.
Is DTC B1238 or N Indicated?
YES - Go to step 4.
NO - Intermittent failure, check for loose wires or poor connections on the passenger's control motor circuit.
4. Turn the ignition switch OFF.
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, or repair the passenger's air mix control linkage or door.
6. Disconnect the passenger's air mix control motor 7P connector.
7. Disconnect the climate control unit 30P connector.
8. Check for continuity between the following terminals of climate control unit 30P connector and the passenger's air mix control motor 7P connector.
Is there continuity?
YES - Go to step 9.
NO - Repair open in the wire(s) between the climate control unit and the passenger's air mix control motor.
9. Check for continuity between body ground and climate control unit 30P connector No. 20 and No. 21 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 - Substitute a known-good climate control unit, and recheck. If the symptom/indication goes away, replace the original climate control unit.