B1276

DTC Troubleshooting: B1275, B1276, B1277, B1278

DTC B1275:

Headlight Switch 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 Troubleshooting - B-CAN System Diagnosis Test Mode A.

1. Clear the DTCs with the HDS.

2. Turn the ignition switch to LOCK (0), and then back to ON (II).

3. Turn the combination light switch to the PARKING, AUTO, and ON (low beam) positions, and then to the OFF position.

4. Wait for at least 6 seconds.

5. Check for DTCs with the HDS.

Are DTCs B1275, B1276, B1277, and/or B1278 indicated?

YES -

Go to step 6.

NO -

Intermittent failure, the system is OK at this time. Check for loose or poor connections.

6. Select LIGHTING from the BODY ELECTRICAL SYSTEM SELECT menu, and enter the DATA LIST.

7. Check each combination light switch position value with the DATA LIST menu.

When the combination light switch is turned OFF





When the combination light switch is turned to PARKING LIGHT





When the combination light switch is turned to AUTO





When the combination light switch is turned ON (HEADLIGHT)





Are all data list values correct?

YES -

Faulty driver's MICU; replace the driver's under-dash fuse/relay box, USA models Driver's Under-Dash Fuse/Relay Box (Driver's MICU) Removal and Installation (USA Models), Canada models Driver's Under-Dash Fuse/Relay Box (Driver's MICU) Removal and Installation (Canada Models).

NO -

Go to step 8.

8. Turn the ignition switch to LOCK (0).

9. Disconnect the combination light switch 12P connector.

10. Turn the ignition switch to ON (II).

11. Select LIGHTING from the BODY ELECTRICAL SYSTEM SELECT menu, and enter the DATA LIST.

12. Check each combination light switch position value with the DATA LIST menu.





Are all data list values indicated OFF?

YES -

Go to step 16.

NO -

Go to step 13.

13. Turn the ignition switch to LOCK (0).

14. Disconnect driver's under-dash fuse/relay box connector R (24P).

15. Check for continuity between body ground and driver's under-dash fuse/relay box connector R (24P) terminals No. 6,No. 7, and No. 8 individually.





Is there continuity?

YES -

Repair a short to ground in the wire(s).

NO -

Faulty driver's MICU; replace the driver's under-dash fuse/relay box, USA models Driver's Under-Dash Fuse/Relay Box (Driver's MICU) Removal and Installation (USA Models), Canada models Driver's Under-Dash Fuse/Relay Box (Driver's MICU) Removal and Installation (Canada Models).

16. Turn the ignition switch to LOCK (0).

17. Do the combination light switch test Service and Repair.

Is the combination light switch OK?

YES -

Go to step 18.

NO -

Replace the combination light switch Service and Repair.

18. Disconnect driver's under-dash fuse/relay box connector R (24P).

19. Check for continuity between driver's under-dash fuse/relay box connector R (24P) terminals and the combination light switch 12P connector terminals as shown:









Is there continuity?

YES -

Go to step 20.

NO -

Repair an open or high resistance in the wire(s).

20. Check for continuity between driver's under-dash fuse/relay box connector R (24P) terminals as shown:





Is there continuity?

YES -

Repair a short between the wires.

NO -

Faulty driver's MICU; replace the driver's under-dash fuse/relay box, USA models Driver's Under-Dash Fuse/Relay Box (Driver's MICU) Removal and Installation (USA Models), Canada models Driver's Under-Dash Fuse/Relay Box (Driver's MICU) Removal and Installation (Canada Models).