E and Auto

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 function 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 5P connector (with automatic lighting) or 2P connector (without automatic lighting).

7. Disconnect climate control unit connectors A (28P) and B (12P).

8. Check for continuity between climate control unit connector A (28P) terminal No. 25 and the sunlight sensor 5P connector terminal No. 4 (with automatic lighting) or the sunlight sensor 2P connector terminal No. 1 (without automatic lighting).

Is there continuity?
YES - Go to step 9.

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


With automatic lighting





Without automatic lighting





9. Check for continuity between climate control unit connector B (12P) terminal No. 10 and the sunlight sensor 5P connector terminal No. 2 (with automatic lighting) or the sunlight sensor 2P connector terminal No. 2 (without automatic lighting).

Is there continuity?
YES - Go to step 10.

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


With automatic lighting





Without automatic lighting





10. Reconnect the sunlight sensor 5P connector (with automatic lighting) or 2P connector (without automatic lighting).

11. Reconnect climate control unit connectors A (28P) and B (12P).

12. Test the sunlight sensor. Sunlight Sensor Test

Is the sunlight sensor OK?
YES - Check for loose wires or poor connections at climate control unit connector and at the sunlight sensor 5P connector (with automatic lighting) or the sunlight sensor 2P connector (without automatic lighting). 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