Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
DTC B1229 (07): An Open in the Sunlight Sensor Circuit (2013-15)
| DTC Description | DTC |
|---|---|
| B1229 An open in the sunlight sensor circuit |
DTC (AC)
- Problem verification:
Clear the DTC with the HDS.
Clear DTCs
- 2. Press the engine start/stop button to select the OFF mode and then the ON mode.
- 3. Do the Self-Diagnostic Function with the HDS or the climate control unit - Refer to: How to Troubleshoot the Climate Control System (2013-15), or How to Troubleshoot the Body Electrical (2013-15) .
- 4. Check for DTCs.
DTC Description DTC B1229 An open in the sunlight sensor circuit Is DTC B1229 or 07 indicated?
YES
Go to step 2.
NO
Intermittent failure. Check for loose wires or poor connections on the sunlight sensor circuit.
- Open wire check (TSUN line):
Press the engine start/stop button to select the OFF mode.
- 2. Disconnect the following connectors.
Climate control unit connector A (28P) Sunlight sensor 7P connector - 3. Check for continuity between test points 1 and 2.
Test condition OFF mode Climate control unit connector A (28P): disconnected Sunlight sensor 7P connector: disconnected Test circuit TSUN Test point 1 Climate control unit connector A (28P) No. 22 (PUR) Test point 2 Sunlight sensor 7P connector No. 2 (PUR) Is there continuity?
YES
The TSUN wire is not opened. Go to step 3.
NO
Repair an open in the wire between the climate control unit and the sunlight sensor.
- Open wire check (SENSOR COM line):
Disconnect the following connector.
Climate control unit connector B (12P) - 2. Check for continuity between test points 1 and 2.
Test condition OFF mode Climate control unit connector A (28P): disconnected Climate control unit connector B (12P): disconnected Sunlight sensor 7P connector: disconnected Test circuit SENSOR COM Test point 1 Climate control unit connector B (12P) No. 10 (BLK) Test point 2 Sunlight sensor 7P connector No. 3 (BLK) Is there continuity?
YES
The SENSOR COM wire is OK. Go to step 4.
NO
Repair an open in the wire between the climate control unit and the sunlight sensor.
- Shorted wire check (TSUN line to S 5V/SENSOR 5V line):
Check for continuity between test points 1 and 2.
Test condition OFF mode Climate control unit connector A (28P): disconnected Climate control unit connector B (12P): disconnected Sunlight sensor 7P connector: disconnected Test circuit TSUN, S 5V Test point 1 Climate control unit connector A (28P) No. 22 (PUR) Test point 2 Climate control unit connector B (12P) No. 1 (BLK) Is there continuity?
YES
Repair a short in the wires between the climate control unit and the sunlight sensor.
NO
The TSUN wire and S 5V/SENSOR 5V wire are OK. Go to step 5.
- Sunlight sensor check:
Reconnect climate control unit connector A (28P) and B (12P) .
- 2. Test the sunlight sensor .
Is the sunlight sensor OK?
YES
Replace the climate control unit .
NO
NO RELATED
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.