DTC Troubleshooting: B1128
DTC B1128: Driver's Door Remote Switch Input Circuit Malfunction (Simultaneous input of lock and unlock signal)
DTC Description
DTC
B1128 Driver's door remote switch input Circuit Malfunction (Simultaneous input of lock and unlock signal)
  

NOTE: Refer to the Electrical Wiring Diagrams for the location of the under-dash fuse/relay box connectors.

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

Keyless/power door locks/security system check 1
?1.
With the driver's door lock switch in the neutral position, check the parameter(s) below with the HDS.
Signal
Current conditions
Values
Unit
Driver's Door Lock Switch(LOCK)
    
Driver's Door Lock Switch(UNLOCK)
    

Is either information indicator ON?

     
YES
     
     
     
Go to step 4.
     
NO
     
     
     
Go to step 2.
2.
Keyless/power door locks/security system check 2:

Keyless/power door locks/security system check 2
?1.
With the driver's door lock switch in the lock position, check the parameter(s) below with the HDS.
Signal
Current conditions
Values
Unit
Driver's Door Lock Switch(LOCK)
    
Driver's Door Lock 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 (REMOTE SW UNLOCK to REMOTE SW LOCK line):

Shorted wire check (REMOTE SW UNLOCK to REMOTE SW LOCK line)
?1.
Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.

?2.
Disconnect the following connector.

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


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

Are both information indicators ON?

     
YES
     
     
     
Repair a short between the wires.?
     
NO
     
     
     
The REMOTE SW UNLOCK to REMOTE SW LOCK wire is OK. Faulty door lock switch; replace the power window master switch.?
4.
Keyless/power door locks/security system check 2:

Keyless/power door locks/security system check 2
?1.
Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.

?2.
Disconnect the following connector.

?3.
Check the parameter(s) below with the HDS.
Signal
Current conditions
Values
Unit
Driver's Door Lock Switch(LOCK)
    
Driver's Door Lock Switch(UNLOCK)
    

Is either information indicator ON?

     
YES
     
     
     
Go to step 5.
     
NO
     
     
     
Faulty door lock switch; replace the power window master switch.?
5.
Shorted wire check (REMOTE SW UNLOCK, REMOTE SW LOCK lines):

Shorted wire check (REMOTE SW UNLOCK, REMOTE SW LOCK lines)
?1.
Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.

?2.
Disconnect the following connector.

?3.
Check for continuity between test points 1 and 2 individually.
Test condition
IG LOCK (0) or OFF mode
Power window master switch 26P connector: disconnected
Under-dash fuse/relay box connector P (24P): disconnected
Test circuit
REMOTE SW UNLOCK
Test point 1
Under-dash fuse/relay box connector P (24P) No. 6 (PNK)
Test point 2
Body ground

Test circuit
REMOTE SW LOCK
Test point 1
Under-dash fuse/relay box connector P (24P) No. 5 (GRN)
Test point 2
Body ground


Are there continuity?

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