B1129

DTC Troubleshooting: B1129

DTC B1129: Driver's Door Lock Knob Switch Input Circuit Malfunction (Simultaneous input of lock and unlock signal)

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 knob switch several times.

4. Check for DTCs with the HDS.

Is DTC B1129 indicated?
YES - Go to step 5.

NO - Intermittent failure, the system is OK at this time. Check for loose or poor connections.


5. Select KEYLESS from the BODY ELECTRICAL menu, and enter the DATA LIST.

6. Check the ON/OFF information of the DRIVER'S DOOR LOCK KNOB SWITCH (LOCK) and the DRIVER'S DOOR LOCK KNOB SWITCH (UNLOCK).

Are the DRIVER'S DOOR LOCK KNOB SWITCH (LOCK) information indicator ON and the DRIVER'S DOOR LOCK KNOB SWITCH (UNLOCK) information indicator OFF with the driver's door lock knob switch in LOCK position, and are the DRIVER'S DOOR LOCK KNOB SWITCH (LOCK) information indicator OFF and the DRIVER'S DOOR LOCK KNOB SWITCH (UNLOCK) information indicator ON with the driver's door lock knob switch in UNLOCK position?
YES - Faulty MICU, replace the under-dash fuse/relay box. Under-Dash Fuse/Relay Box Removal And Installation (USA Models)

NO - Go to step 7.


7. Disconnect the driver's door lock actuator 10P connector.

8. Check the ON/OFF information of the DRIVER'S DOOR LOCK KNOB SWITCH (LOCK) and DRIVER'S DOOR LOCK KNOB SWITCH (UNLOCK) in the DATA LIST.

Are both information indicators OFF?
YES - Check for an open in the driver's door lock knob switch (LOCK) wire or the driver's door lock knob switch (UNLOCK) wire between the MICU and the driver's door lock knob switch. If OK, replace the driver's door lock actuator.

NO - Go to step 9.


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

10. Disconnect under-dash fuse/relay box connector E (12P).

11. Check for continuity between under-dash fuse/relay box connector E (12P) terminals No. 2 (UNLOCK) and No. 9 (LOCK) and body ground individually.

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

NO - Go to step 12.






12. Check for continuity between under-dash fuse/relay box connector E (12P) terminals No. 2 (UNLOCK) and No. 9 (LOCK).

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

NO - Faulty MICU, replace the under-dash fuse/relay box. Under-Dash Fuse/Relay Box Removal And Installation (USA Models)