B1229

DTC B1229 or DTC indicator E: An Open in the Sunlight Sensor Circuit

1. Clear the DTC by turning the ignition switch OFF, and then ON (II).
2. Operate the climate control system in several modes.
3. Check for DTCs using the self-diagnostic or HDS.

Is DTC B1229 or E indicated?

YES - Go to step 4.

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

4. Turn the ignition switch OFF.
5. Test the sunlight sensor.

Is the sunlight sensor OK?

YES - Go to step 6.

NO - Replace the sunlight sensor.

6. Disconnect the sunlight sensor 2P connector.
7. Disconnect climate control unit connector A (20P).




8. Check for continuity between the No. 17 terminal of climate control unit connector A (20P) and the No. 2 terminal of the sunlight sensor 2P connector.

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 No. 5 terminal of climate control unit connector A (20P) and the No. 1 terminal of the sunlight sensor 2P connector.

Is there continuity?

YES - Check for loose wires or poor connections at climate control unit connector A (20P) 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 - Repair open in the wire between the climate control unit and the sunlight sensor.