B1128

DTC Troubleshooting: 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. Troubleshooting - B-CAN System Diagnosis Test Mode A

1. Clear the DTCs with the HDS.

2. Turn the ignition switch to LOCK (0), and then back to ON (II).

3. Operate the driver's door lock switch LOCK/UNLOCK 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 system is OK at this time.


5. With the driver's door lock switch in the neutral position, select KEYLESS from the HDS 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 12.

NO - Go to step 7.


7. Disconnect the power window master switch 22P (16P)* connector.
*: 2-door

8. 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 door lock switch; replace the power window master switch. Power Window Master Switch Test/Replacement (4-Door)

NO - Go to step 9.


9. Turn the ignition switch to LOCK (0).

10. Disconnect under-dash fuse/relay box connector T (34P).

11. Check for continuity between under-dash fuse/relay box connector T (34P) terminals No. 28 (LOCK) and No. 27 (UNLOCK) and body ground.

Is there continuity?
YES - Repair a short in the LOCK or UNLOCK wire.

NO - Faulty MICU, replace the under-dash fuse/relay box. Under-Dash Fuse/Relay Box Removal and Installation






12. Turn the ignition switch to LOCK (0).

13. Disconnect the power window master switch 22P (16P)* connector.
*: 2-door

14. Disconnect under-dash fuse/relay box connector T (34P).

15. Check for continuity between under-dash fuse/relay box connector T (34P) terminals No. 28 (LOCK) and No. 27 (UNLOCK).

Is there continuity?
YES - Repair a short in the wire between the LOCK and UNLOCK wires.

NO - Substitute a known-good power window master switch, and recheck. If the symptom/indication goes away, replace the original power window master switch. If not, the MICU is faulty, replace the under-dash fuse/relay box. Under-Dash Fuse/Relay Box Removal and Installation