DTC Troubleshooting: B1129
DTC B1129: Driver's door knob switch input circuit malfunction (Simultaneous input of lock and unlock signal)
DTC Description
DTC
B1129 Driver's door knob switch input circuit malfunction (Simultaneous input of lock and unlock signal)
 

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

1.
Keyless/power door locks/security system check:

Keyless/power door locks/security system check
?1.
Turn the vehicle to the ON mode.

?2.
With the driver's door lock knob switch in the lock position, check the parameter(s) below with the HDS.
Signal
Current conditions
Values
Unit
Driver's Door Lock Knob Switch(LOCK)
   
Driver's Door Lock Knob Switch(UNLOCK)
   

Are both information indicators ON?

     
YES
     
     
     
Go to step 2.
     
NO
     
     
     
Intermittent failure, the system is OK at this time.
2.
Determine possible failure area (driver's door latch, others):

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.
Turn the vehicle to the ON mode.

?4.
Check the parameter(s) below with the HDS.
Signal
Current conditions
Values
Unit
Driver's Door Lock Knob Switch(LOCK)
   
Driver's Door Lock Knob Switch(UNLOCK)
   

Is either information indicator ON?

     
YES
     
     
     
Go to step 3.
     
NO
     
     
     
Faulty driver's door lock knob switch; replace the driver's door latch.?
3.
Shorted wire check (DR SILCON UNLOCK, DR SILCON LOCK lines):

Shorted wire check (DR SILCON UNLOCK, DR SILCON LOCK lines)
?1.
Turn the vehicle to the OFF (LOCK) mode.

?2.
Disconnect the following connector.
Under-dash fuse/relay box connector D (24P)

?3.
Check for continuity between test points 1 and 2 individually.
Test condition
Vehicle OFF (LOCK) mode
Driver's door latch 10P connector: disconnected
Under-dash fuse/relay box connector D (24P): disconnected
Test point 1
Test point 2
Body ground

Test point 1
Test point 2
Body ground

Is there continuity?

     
YES
     
     
     
Repair a short to ground in the wire(s).?
     
NO
     
     
     
The DR SILCON UNLOCK and DR SILCON LOCK wires are OK. Faulty MICU; replace the under-dash fuse/relay box.?