L and Auto

DTC Troubleshooting: B1235 or Indicator L and AUTO

DTC B1235 or DTC indicator L and AUTO: A Problem in the Driver's Air Mix Control Linkage, Door, or Motor Circuit

1. Clear the DTC with the HDS.

2. Turn the ignition switch to LOCK (0), and then to ON (II), or press the engine start/stop button to select the OFF mode, and then the ON mode.

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

4. Check for DTCs.

Is DTC B1235 or L and AUTO indicated?
YES - Go to step 5.

NO - Intermittent failure. Check for loose wires or poor connections on the driver's air mix control motor circuit.


5. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.

6. Test the driver's air mix control motor. Driver's Air Mix Control Motor Test

Is the driver's air mix control motor OK?
YES - Go to step 7.

NO - Replace the driver's air mix control motor, Driver's Air Mix Control Motor Replacement or repair the driver's air mix control linkage or door.


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

8. Disconnect climate control unit connector A (32P).

9. Check for continuity between the following terminals of climate control unit connector A (32P) and the driver's air mix control motor 7P connector.





Is there continuity?
YES - Go to step 10.

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






10. Check for continuity between body ground and climate control unit connector A (32P) terminals No. 11 and No. 12 individually.

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