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 B1275, B1276, B1277, B1278
DTC B1275 : Headlight OFF Position Circuit Malfunction
DTC B1276 : Headlight Switch Parking Position Circuit Malfunction
DTC B1277 : Headlight AUTO Position Circuit Malfunction
DTC B1278 : Headlight ON Position Circuit Malfunction
NOTE: If you are troubleshooting multiple DTCs, be sure to follow the instructions in B-CAN System Diagnosis Test Mode A .
| DTC Description | DTC |
|---|---|
| B1275 Headlight OFF Position Circuit Malfunction | |
| B1276 Headlight Switch Parking Position Circuit Malfunction |
| DTC Description | DTC |
|---|---|
| B1277 Headlight AUTO Position Circuit Malfunction | |
| B1278 Headlight ON Position Circuit Malfunction |
DTC (Body Control Module)
- Problem verification
-1. Check the parameter(s) below with the HDS.
When the combination light switch is turned OFF
Signal Threshold Current conditions Values Unit Values Unit Headlight Switch (OFF) ON Headlight Switch (PARKING) OFF Headlight Switch (AUTO) OFF Headlight Switch (HEADLIGHT) OFF When the combination light switch is turned to POSITION (PARKING)
Signal Threshold Current conditions Values Unit Values Unit Headlight Switch (OFF) OFF Headlight Switch (PARKING) ON Headlight Switch (AUTO) OFF Headlight Switch (HEADLIGHT) OFF When the combination light switch is turned to AUTO
Signal Threshold Current conditions Values Unit Values Unit Headlight Switch (OFF) OFF Headlight Switch (PARKING) OFF Headlight Switch (AUTO) ON Headlight Switch (HEADLIGHT) OFF When the combination light switch is turned ON (HEADLIGHT)
Signal Threshold Current conditions Values Unit Values Unit Headlight Switch (OFF) OFF Headlight Switch (PARKING) ON Headlight Switch (AUTO) OFF Headlight Switch (HEADLIGHT) ON Are all data list values correct?
YES
Intermittent failure, the system is OK at this time. Check for loose or poor connections.
NO
Go to step 2.
- Exterior lights system check
-1. Check the parameter(s) below with the HDS.
Cycle through all switch selections
Signal Current conditions Values Unit Headlight Switch (OFF) Headlight Switch (PARKING) Headlight Switch (AUTO) Headlight Switch (HEADLIGHT) Is any data list value OFF, not ON?
YES
Go to step 5.
NO
Go to step 3.
- Determine possible failure area (combination light switch, others)
-1. Turn the vehicle to the OFF (LOCK) mode.
-2. Disconnect the following connector.
Combination light switch 12P connector -3. Check the parameter(s) below with the HDS.
Signal Current conditions Values Unit Headlight Switch (OFF) Headlight Switch (PARKING) Headlight Switch (AUTO) Headlight Switch (HEADLIGHT) Are all data lists values OFF?
YES
Replace the combination light switch .
NO
Go to step 4.
- Shorted wire check (H/L OFF SW, H/L ON SW, PARKING LT SW lines)
-1. Turn the vehicle to the OFF (LOCK) mode.
-2. Disconnect the following connector.
Body control module connector C (28P) -3. Check for continuity between test points 1 and 2 individually.
Test condition Vehicle OFF (LOCK) mode
Combination light switch 12P connector: disconnected
Body control module connector C (28P): disconnectedTest point 1 Body control module connector C (28P) No. 10 Test point 2 Body ground Test point 1 Body control module connector C (28P) No. 9 Test point 2 Body ground Test point 1 Body control module connector C (28P) No. 11 Test point 2 Body ground Is there continuity?
YES
Repair a short to ground in the wire.
NO
The H/L OFF SW, H/L ON SW, and PARKING LT SW wires are OK. Replace the body control module .
- Determine possible failure area (combination light switch, others)
-1. Turn the vehicle to the OFF (LOCK) mode.
-2. Disconnect the following connector.
Combination light switch 12P connector -3. Connect terminals A and B with jumper wires.
Terminal A Combination light switch 12P connector No. 1 Terminal B Body ground Terminal A Combination light switch 12P connector No. 7 Terminal B Body ground Terminal A Combination light switch 12P connector No. 8 Terminal B Body ground -4. Check the parameter(s) below with the HDS.
Signal Current conditions Values Unit Headlight Switch (OFF) Headlight Switch (PARKING) Headlight Switch (AUTO) Headlight Switch (HEADLIGHT) Has the data list value changed from OFF to ON?
YES
Replace the combination light switch .
NO
Go to step 6.
- Open wire check (H/L OFF SW, H/L ON SW, PARKING LT SW, COMBI SW GND (LT) lines)
-1. Turn the vehicle to the OFF (LOCK) mode.
-2. Disconnect the following connector.
Body control module connector C (28P) -3. Check for continuity between test points 1 and 2 respectively.
Test condition Vehicle OFF (LOCK) mode
Body control module connector C (28P): disconnected
Combination light switch 12P connector: disconnectedTest point 1 Body control module connector C (28P) No. 10 Test point 2 Combination light switch 12P connector No. 1 Test point 1 Body control module connector C (28P) No. 9 Test point 2 Combination light switch 12P connector No. 7 Test point 1 Body control module connector C (28P) No. 11 Test point 2 Combination light switch 12P connector No. 8 Test point 1 Body control module connector C (28P) No. 3 Test point 2 Combination light switch 12P connector No. 6 Is there continuity?
YES
The H/L OFF SW, H/L ON SW, PARKING LT SW, and COMBI SW GND (LT) wires are OK. Replace the body control module .
NO
Repair an open or high resistance in the wire.
NO RELATED
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
Affiliate disclosure: We may earn a commission at no extra cost to you.
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.