B1128

DTC B1128: Driver's Door Lock Switch Signal Error

NOTE: If you are troubleshooting multiple DTCs, be sure to follow the instructions in B-CAN system diagnosis test mode A.

1. Clear the DTCs with the HDS.
2. Turn the ignition switch OFF, and then back ON (II).
3. Operate the driver's door look switch several times.
4. Check for DTCs with the HDS.

Is DTC B1128 indicated?

YES - Go to step 5.

NO - Intermittent failure. The driver's door lock switch system is OK at this time. Check for shorted wires.

5. With the driver's door lock switch in the neutral position, select SECURITY from the BODY ELECTRICAL SYSTEM SELECT MENU, and enter the DATA LIST.
6. Check the ON/OFF information of the Driver's Door Lock Switch (LOCK) and Driver's Door Lock Switch (UNLOCK) in the DATA LIST.

Are both information indicators OFF?

YES - Go to step 7.

NO - Check the door lock switch. If the driver's door lock switch is OK, faulty door multiplex control unit; replace the power window master switch.

7. Push the driver's door lock switch in LOCK and UNLOCK positions, and check the ON/OFF information of the Driver's Door Lock Switch (LOCK) and Driver's Door Lock Switch (UNLOCK) in the DATA LIST.

Does the Driver's Door Lock Switch (LOCK) (Driver's Door Lock Switch (UNLOCK)) information indicate ON when the door lock switch is pushed in the LOCK (UNLOCK) position, and OFF when the door lock switch is released?

YES - Faulty door multiplex control unit; replace the power window master switch.

NO - Go to step 8.

8. Turn the ignition switch OFF.
9. Disconnect the driver's door lock switch 5P connector and power window master switch connector A (22P).




10. Check for continuity between the No. 1 terminal and the No. 3 terminal of the driver's door lock switch 5P connector.

Is there continuity?

YES - Repair short in the WHT/BLU (LOCK) and WHT/GRN (UNLOCK) wires.

NO - Faulty driver's door lock switch.

11. Remove the driver's door panel.
12. Disconnect the 5P connector from the driver's door lock switch.
13. Check the ON/OFF information of the Driver's Door Lock Switch (LOCK) and Driver's Door Lock Switch (UNLOCK) in the DATA LIST.

Are both information indicators OFF?

YES - Faulty driver's door lock switch; replace if

NO - Go to step 14.

14. Turn the ignition switch OFF.
15. Check for a short in the wire between the MICU and driver's door lock switch using the keyless entry/security alarm control unit input test.

Are the wire harnesses OK?

YES - Faulty MICU; replace it.

NO - A short in the wire, repair and recheck.