DTC B1279

DTC B1279  : Dimmer Switch Circuit Malfunction

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

DTC (Body Control Module)

1. Exterior lights system check 1

   -1. With the headlight dimmer switch in the neutral position, check the parameter (s) below with the HDS.

   Signal	Current conditions
   	Values	Unit
   Headlight Switch (HIGH BEAM)
   Headlight Switch (PASSING)

   Is either information indicator ON?

   YES 

   Go to step  4.

   NO 

   Go to step 2.

2. Exterior lights system check 2

   -1. With the headlight dimmer switch in the high beam position, check the parameter (s) below with the HDS.

   Signal	Current conditions
   	Values	Unit
   Headlight Switch (HIGH BEAM)
   Headlight Switch (PASSING)

   Are both information indicators ON?

   YES 

   Go to step 3.

   NO 

   Intermittent failure, the system is OK at this time.

3. Shorted wire check (H/L HI SW to PASSING SW line)

   -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	Body control module connector C (28P) No. 8
   Terminal B	Body ground

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

   Signal	Current conditions
   	Values	Unit
   Headlight Switch (HIGH BEAM)
   Headlight Switch (PASSING)

   Are both information indicators ON?

   YES 

   Repair a short between the wires.

   NO 

   The H/L HI SW to PASSING SW wire is OK. Replace the combination light switch .

4. 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 (HIGH BEAM)
   Headlight Switch (PASSING)

   Is either information indicator ON?

   YES 

   Go to step 5.

   NO 

   Replace the combination light switch .

5. Shorted wire check (PASSING SW, H/L HI 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): disconnected
   Test point 1	Body control module connector C (28P) No. 7
   Test point 2	Body ground

   Test point 1	Body control module connector C (28P) No. 8
   Test point 2	Body ground

   Are there continuity?

   YES 

   Repair a short to ground in the wire.

   NO 

   The PASSING SW and H/L HI SW wires are OK. Replace the body control module .