B1128

Control System DTCs

DTC Troubleshooting: B1128

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:

-1. With the driver's door lock switch in the neutral position, check the parameter(s) below with the HDS.





Is either information indicator ON?
-YES- Go to step 4.
-NO- Go to step 2.

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.





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):

-1. Turn the ignition switch to LOCK (0).

-2. Disconnect the following connector.





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









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





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 Power Window Master Switch Removal And Installation.

4. Keyless/power door locks/security system check 2:

-1. Turn the ignition switch to LOCK (0).

-2. Disconnect the following connector.





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





Is either information indicator ON?
-YES- Go to step 5.
-NO- Faulty door lock switch; replace the power window master switch Power Window Master Switch Removal And Installation.

5. Shorted wire check (REMOTE SW UNLOCK, REMOTE SW LOCK lines):

-1. Turn the ignition switch to LOCK (0).

-2. Disconnect the following connector.





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














Is 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 Under-Dash Fuse/Relay Box Removal and Installation.