DTC Troubleshooting: B1128

DTC B1128:  Driver's Door Lock Switch Signal Error


1.Clear the DTCs with the HDS.

2.Turn the ignition switch OFF, and then back ON (II).

3.Operate the driver's door lock switch several times.

4.Check for DTCs with the HDS.

Is DTC B1128 indicated?


YES - Go to 5.


NO - Intermittent failure. The communication bus line is OK at this time. Check for loose or poor connections, or worn/shorted wires. If the connections are good, check the battery condition and the charging system.n


5.With the driver's door lock switch in the neutral position, check the ON/OFF information of the SW ICU DRRMLK and SW ICU DRRMUNLK in the DATA LIST with the HDS.

Are both information indicators OFF?


YES - Faulty MICU; replace the under-dash fuse/relay box.n


NO - Go to 6.


6.Disconnect the power window master switch 22P connector.

7.Check the ON/OFF information of the SW ICU DRRMLK and SW ICU DRRMUNLK with the HDS.

Are both information indicators OFF?


YES - Faulty driver's door lock switch.n


NO - Go to 8.


8.Turn the ignition switch OFF.

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

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

 

Is there continuity?


YES - Repair a short in the wire.n


NO - Go to 11.

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

 

Is there continuity?


YES - Repair a short in the wire.n


NO - Faulty MICU; replace the under-dash fuse/relay box.n