DTC Troubleshooting: B1229 (E)

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


1.Clear the DTC with the HDS.

2.Turn the ignition switch OFF, and then ON (II).

3.Do the self-diagnostic with the HDS or climate control unit.

4.Check for DTCs.

Is DTC B1229 or E indicated?


YES - Go to 5.


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


5.Turn the ignition switch OFF.

6.Disconnect the sunlight sensor 2P connector.

7.Disconnect the climate control unit 32P connector.

8.Check for continuity between the climate control unit 32P connector terminal No. 24 and the sunlight sensor 2P connector terminal No. 2.

 

Is there continuity?


YES - Go to 9.


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

9.Check for continuity between the climate control unit 32P connector terminal No. 19 and the sunlight sensor 2P connector terminal No. 1.

 

Is there continuity?


YES - Go to 10.


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


10.Reconnect the sunlight sensor 2P connector.

11.Reconnect the climate control unit 32P connector.

12.Test the sunlight sensor.

Is the sunlight sensor OK?


YES - Check for loose wires or poor connections at the climate control unit 32P connector 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


NO - Replace the sunlight sensor.n