B1229

DTC Troubleshooting: B1229 or Indicator E and AUTO

DTC B1229 or DTC indicator E and AUTO:An Open 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 B1229 or E and AUTO indicated?
YES - Go to step 5.

NO - Intermittent failure, check for loose wires or poor connections on the sunlight sensor circuit.


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 the climate control unit connector B (16P) No. 13 terminal and the sunlight sensor 2P connector No. 2 terminal.

Is there continuity?
YES - Go to step 9.

NO - Repair open in the wire between the climate control unit and the sunlight sensor.






9. Check for continuity between the climate control unit connector B (16P) No. 4 terminal and the sunlight sensor 2P connector No. 1 terminal.

Is there continuity?
YES - Go to step 10.

NO - Repair open in the wire between the climate control unit and the sunlight sensor.






10. Test the sunlight sensor. Sunlight Sensor Test

Is the sunlight sensor OK?
YES - Check for loose wires or poor connections at the climate control unit connector B (16P) and at the sunlight sensor 2P connector. If the connections are good, 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