B1275

DTC Troubleshooting: B1275, B1276, B1278

DTC B1275: Combination Light Switch OFF Position Circuit Malfunction

DTC B1276: Combination Light Switch Parking (SMALL) Position Circuit Malfunction

DTC B1278: Combination Light Switch ON Position Circuit Malfunction

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 (SMALL) and ON (low beam) positions for at least 6 seconds in each position, and then to the OFF position.

4. Check for DTCs with the HDS.

Is DTC B1275, B1276, or B1278 indicated?
YES - Go to step 5.

NO - Intermittent failure, the system is OK at this time. Check for loose or poor connections.


5. Select LIGHTING from the BODY ELECTRICAL system select menu, and enter DATA LIST.

6. 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 (SMALL):





When the combination light switch is turned ON (HEADLIGHT):





Are all data list values correct?
YES - Faulty MICU, replace the under-dash fuse/relay box. Under-Dash Fuse/Relay Box Removal And Installation (USA Models)

NO - Go to step 7.


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

8. Disconnect the combination light switch 12P connector.

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

10. Select LIGHTING from the BODY ELECTRICAL system select menu, and enter DATA LIST.

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

When the combination light switch is turned OFF:





Are all data list values indicated OFF?
YES - Go to step 15.

NO - Go to step 12.


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

13. Disconnect under-dash fuse/relay box connector M (34P).

14. Check for continuity between under-dash fuse/relay box connector M (34P) terminals No. 5, No. 7, and No. 8 and body ground individually.

Is there continuity?
YES - Repair a short to ground in the wires.

NO - Faulty MICU, replace the under-dash fuse/relay box. Under-Dash Fuse/Relay Box Removal And Installation (USA Models)






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

16. Do the combination light switch test. Combination Light Switch Test/Replacement

Is the combination light switch OK?
YES - Go to step 17.

NO - Replace the combination light switch.


17. Disconnect under-dash fuse/relay box connector M (34P).

18. Check for continuity between under-dash fuse/relay box connector M (34P) terminals and the combination light switch 12P connector terminals as shown:





Is there continuity?
YES - Go to step 19.

NO - Repair open in the wires.






19. Check for continuity between under-dash fuse/relay box connector M (34P) terminals as shown:





Is there continuity?
YES - Repair short between the wires.

NO - Faulty MICU; replace the under-dash fuse/relay box. Under-Dash Fuse/Relay Box Removal And Installation (USA Models)