DTC B1275, B1276, B1277, B1278

DTC B1275  : Headlight OFF position circuit malfunction

DTC B1276  : Headlight switch parking (small) position circuit malfunction

DTC B1277  : Headlight AUTO position circuit malfunction

DTC B1278  : Headlight ON position circuit malfunction

DTC (MICU)

NOTE:  If you are troubleshooting multiple DTCs, be sure to follow the instructions in B-CAN System Diagnosis Test Mode A .

1. 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 (SMALL)	OFF
   Headlight Switch (AUTO)	OFF
   Headlight Switch (HEADLIGHT)	OFF

   When the combination light switch is turned to PARKING (SMALL) 

   Signal	Threshold		Current conditions
   	Values	Unit	Values	Unit
   Headlight Switch (OFF)	OFF
   Headlight Switch (SMALL)	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 (SMALL)	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 (SMALL)	OFF
   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.

2. Exterior lights system check

   -1. Check the parameter(s) below with the HDS.

   Signal	Current conditions
   	Values	Unit
   Headlight Switch (OFF)
   Headlight Switch (SMALL)

   Signal	Current conditions
   	Values	Unit
   Headlight Switch (AUTO)
   Headlight Switch (HEADLIGHT)

   Is data list value OFF, not ON?

   YES 

   Go to step  5.

   NO 

   Go to step 3.

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 (SMALL)
   Headlight Switch (AUTO)
   Headlight Switch (HEADLIGHT)

   Has the data list value changed from ON to OFF?

   YES 

   Replace the combination light switch .

   NO 

   Go to step 4.

4. Shorted wire check (H/L OFF SW, H/L ON SW, SMALL LT SW lines)

   -1. Turn the vehicle to the OFF (LOCK) mode.

   -2. Disconnect the following connector.

   Under-dash fuse/relay box connector N (20P)

   -3. Check for continuity between test points 1 and 2.

   Test condition	Vehicle OFF (LOCK) mode Combination light switch 12P connector: disconnected Under-dash fuse/relay box connector N (20P): disconnected
   Test point 1	Under-dash fuse/relay box connector N (20P) No. 18
   Test point 2	Body ground

   Test point 1	Under-dash fuse/relay box connector N (20P) No. 19
   Test point 2	Body ground

   Test point 1	Under-dash fuse/relay box connector B (20P) No. 20
   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 SMALL LT SW wires are OK. Faulty MICU; replace the under-dash fuse/relay box .

5. 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 a jumper wire.

   Terminal A	Combination light switch 12P connector (female terminals) No. 1:
   Terminal B	Body ground

   Terminal A	Combination light switch 12P connector (female terminals) No. 7:
   Terminal B	Body ground

   Terminal A	Combination light switch 12P connector (female terminals) No. 8:
   Terminal B	Body ground

   Courtesy of HONDA, U.S.A., INC.

   -4. Check the parameter(s) below with the HDS.

   Signal	Current conditions
   	Values	Unit
   Headlight Switch (OFF)
   Headlight Switch (SMALL)
   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.

6. Open wire check (H/L OFF SW, H/L ON SW, SMALL LT SW, COMBI SW GND(LT) lines)

   -1. Turn the vehicle to the OFF (LOCK) mode.

   -2. Disconnect the following connector.

   Under-dash fuse/relay box connector N (20P)

   -3. Check for continuity between test points 1 and 2.

   Test condition	Vehicle OFF (LOCK) mode Under-dash fuse/relay box connector N (20P): disconnected Combination light switch 12P connector: disconnected
   Test point 1	Under-dash fuse/relay box connector N (20P) No. 18

   Test point 2

   Combination light switch 12P connector (female terminals) No. 1:

   Test point 1	Under-dash fuse/relay box connector N (20P) No. 19
   Test point 2	Combination light switch 12P connector (female terminals) No. 7:

   Test point 1	Under-dash fuse/relay box connector N (20P) No. 20
   Test point 2	Combination light switch 12P connector (female terminals) No. 8:

   Test point 1	Under-dash fuse/relay box connector N (20P) No. 1
   Test point 2	Combination light switch 12P connector (female terminals) No. 6:

   Courtesy of HONDA, U.S.A., INC.

   Is there continuity?

   YES 

   The H/L OFF SW, H/L ON SW, SMALL LT SW, and COMBI SW GND(LT) wires are OK. Faulty MICU; replace the under-dash fuse/relay box .

   NO 

   Repair an open or high resistance in the wire.