DTC B1127: Driver's Door Lock Key Cylinder Switch Malfunction

DTC (Door Multiplex Control Unit)

• 1. Problem verification (driver's door key cylinder switch in the neutral position):

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

  Signal	Current conditions
  	Values	Unit
  Driver's Door Key Cylinder Switch(LOCK)
  Driver's Door Key Cylinder Switch(UNLOCK)

  Is either information indicator ON?

  YES 

  Go to step 4.

  NO 

  Go to step 2.

• 2. Problem verification (driver's door key cylinder switch in the lock position):

  1. With the driver's door key cylinder in the lock position, check the parameter(s) below with the HDS.

  Signal	Current conditions
  	Values	Unit
  Driver's Door Key Cylinder Switch(LOCK)
  Driver's Door Key Cylinder Switch(UNLOCK)

  Are both information indicators ON?

  YES 

  Go to step 3.

  NO 

  Intermittent failure, the system is OK at this time.

• 3. Shorted wire check (DR KEY CYL UNLOCK to DR KEY CYL LOCK line):

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

  2. Disconnect the following connector.

  Driver's door latch 10P connector

  3. Connect terminals A and B with a jumper wire.

  Terminal A	Power window master switch 37P connector No. 35
  Terminal B	Body ground

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

  Signal	Current conditions
  	Values	Unit
  Driver's Door Key Cylinder Switch(LOCK)
  Driver's Door Key Cylinder Switch(UNLOCK)

  Are both information indicators ON?

  YES 

  Repair a short between the wires.

  NO 

  The DR KEY CYL UNLOCK to DR KEY CYL LOCK wire is OK. Faulty driver's door key cylinder switch; replace the driver's door latch .

• 4. Determine possible failure area (driver's door latch, others):

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

  2. Disconnect the following connector.

  Driver's door latch 10P connector

  3. Check the parameter(s) below with the HDS.

  Signal	Current conditions
  	Values	Unit
  Driver's Door Key Cylinder Switch(LOCK)
  Driver's Door Key Cylinder Switch(UNLOCK)

  Is either information indicator ON?

  YES 

  Go to step 5.

  NO 

  Faulty driver's door key cylinder switch; replace the driver's door latch .

• 5. Shorted wire check (DR KEY CYL UNLOCK, DR KEY CYL LOCK lines):

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

  2. Disconnect the following connector.

  Power window master switch 37P connector

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

  Test condition	Vehicle OFF (LOCK) mode Driver's door latch 10P connector: disconnected Power window master switch 37P connector: disconnected
  Test point 1	Power window master switch 37P connector No. 34 - Refer to: Power Window Master Switch Input Test(Without Door Multiplex Control Unit)Power Window Master Switch Input Test(With Door Multiplex Control Unit)
  Test point 2	Body ground

  Test point 1	Power window master switch 37P connector No. 35 - Refer to: Power Window Master Switch Input Test(Without Door Multiplex Control Unit)Power Window Master Switch Input Test(With Door Multiplex Control Unit)
  Test point 2	Body ground

  Is there continuity?

  YES 

  Repair a short to ground in the wire.

  NO 

  The DR KEY CYL UNLOCK and DR KEY CYL LOCK wires are OK. Replace the power window master switch .