DTC Troubleshooting: B1229 (E)

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


1.Clear the DTC.

2.Turn the ignition switch OFF, and then ON.

3.Operate the climate control system is several modes.

4.Check the DTCs.

Is DTC E or B1229 indicated?


YES - Go to 5.


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


5.Disconnect the sunlight sensor 2P connector.

6.Disconnect climate control unit connector A (22P).

7.Check for continuity between the No. 13 terminal of climate control unit connector A (22P) and the No. 2 terminal of the sunlight sensor 2P connector.


Is there continuity?


YES - Go to 8.


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

8.Check for continuity between the No. 15 terminal of climate control unit connector A (22P) and the No. 2 terminal of the sunlight sensor 2P connector.


Is there continuity?


YES - Go to 9.


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


9.Reconnect the sunlight sensor 2P connector.

10.Reconnect climate control unit connector A (22P).

11.Test the sunlight sensor.

Is the sunlight sensor OK?


YES - Go to 12.


NO - Replace the  sunlight sensor.n


12.Perform the A/C communication in the Self-Diagnostic Function to obtain the IS-BUS communication verification status.

Is the communication OK?


YES - Check for loose wires or poor connections at climate control unit connector A (22P) and at the sunlight sensor 2P connector. If the connections are good, substitute a known-good climate control unit and printed circuit board, and recheck. If the symptom/indication goes away, replace the original climate control unit and printed circuit board.n


NO - Check for loose wires or poor connections at climate control unit connector A (22P) 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.n