DTC B1127: Driver's Door Key Cylinder Switch Signal Error 1.
Clear the DTCs using the HDS.
2.
Cycle the ignition switch to OFF, and then back ON.
3.
Operate the driver's door key cylinder.
4.
Check for DTCs using the HDS.
Is DTC B1127 indicated?
YES - Go to step 5.
NO - Intermittent failure. The driver's door key cylinder system is OK at this time. Check pinfits and connections.
5.
With no driver's door key cylinder operation, select SECURITY from the HDS, and enter the DATA LIST.
6.
Check the ON/OFF information of the Driver's Door Key Cylinder Switch (LOCK) and Driver's Door Key Cylinder Switch (UNLOCK) in the DATA LIST.
Are both information indicators OFF?
YES - Go to step 7.
NO - Go to step 10.
7.
Turn the driver's door key cylinder to the LOCK and UNLOCK positions with the ignition key and check the ON/OFF information of the Driver's Door Key Cylinder Switch (LOCK) and Driver's Door Key Cylinder Switch (UNLOCK) in the DATA LIST.
Is the Driver's Door Key Cylinder Switch (LOCK) (Driver's Door Key Cylinder Switch (UNLOCK)) information indicator ON when the key cylinder is in the LOCK (UNLOCK) position, and OFF when the key is returned to the neutral position?
YES - Intermittent failure, the door multiplex control unit (power window master switch) is OK at this time. Check pinfits and connections.
NO - Go to step 8.
8.
Disconnect the driver's door key cylinder switch 3P connector.
9.
Check for continuity between the No. 3 (LOCK) and No. 1 (UNLOCK) terminals of the driver's door key cylinder switch 3P connector and the No. 8 (LOCK) and No. 21 (UNLOCK) terminals of the power window master switch 23P connector.
Is there continuity?
YES - Faulty driver's door key cylinder switch.
NO - Repair an open in the WHT/RED or WHT wire.
10.
Disconnect the driver's door key cylinder switch 3P connector.
11.
Check the ON/OFF information of the Driver's Door Key Cylinder Switch (LOCK) and Driver's Door Key Cylinder Switch (UNLOCK) in the DATA LIST.
Are both information indicators OFF?
YES - Faulty driver's door key cylinder switch.
NO - Go to step 12.
12.
Check for continuity between the No. 3 (LOCK) and No. 1 (UNLOCK) terminals of the driver's door key cylinder switch 3P connector and body ground.
Is there continuity?
YES - Repair a short in the WHT/RED or WHT wire.
NO - Faulty door multiplex control unit; replace the power window master switch.
