Operation CHARM: Car repair manuals for everyone.

F and Auto




DTC Troubleshooting: B1230 or Indicator F and AUTO

DTC B1230 or DTC indicator F and AUTO:A Short in the Sunlight Sensor 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 B1230 or F and AUTO indicated?
YES - Go to step 5.

NO - Intermittent failure.


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

6. Disconnect the sunlight sensor 2P connector.

7. Disconnect climate control unit connector B (16P).

8. Check for continuity between body ground and climate control unit connector B (16P) No. 13 terminal.

Is there continuity?
YES - Repair short to body ground in the wire between the climate control unit and the sunlight sensor.

NO - Go to step 9.






9. Check for continuity between the climate control unit connector B (16P) No. 4 and No. 13 terminals.

Is there continuity?
YES - Repair short in the wires between the climate control unit and the sunlight sensor.

NO - Go to step 10.






10. Test the sunlight sensor. Sunlight Sensor Test

Is the sunlight sensor OK?
YES - Substitute a known-good climate control unit, and recheck. If the symptom/indication goes away, replace the original climate control unit.

NO - Replace the sunlight sensor. Service and Repair