DTC Troubleshooting: B1000

DTC B1000:  Communication Bus Line Error

1.Clear the DTCs with the HDS.

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

3.Wait for 6 seconds or more.

4.Check for DTCs with the HDS.

Is DTC B1000 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.Check for DTCs with the HDS.

Are DTCs B1000, B1008, B1011, and B1032 all indicated?


YES - Go to 6.


NO - Go to the indicated DTC troubleshooting.n


6.Turn the ignition switch OFF.

7.Disconnect the appropriate connector at each control unit in the table.

Control Unit Appropriate Connector 
MICU Under-dash fuse/relay box connector Q (16P) 
Gauge control module (tach) 36P connector 
Immobilizer-keyless control unit 7P connector 
Climate control unit 32P connector 

8.Turn the ignition switch ON (II).

9.Clear the DTCs with the HDS.

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

11.Wait for 6 seconds or more.

12.Check for DTCs with the HDS.

Are DTCs B1000, B1008, B1011, and B1032 all indicated?


YES - Replace the  MICU.n


NO - Go to 13.


13.Turn the ignition switch OFF.

14.Check for continuity between the under-dash fuse/relay box connector Q (16P) No. 6 terminal and body ground.

Is there continuity?


YES - Repair the short to ground in the wire.n


NO - Go to 15.


15.Turn the ignition switch ON (II).

16.Check for voltage between the under-dash fuse/relay box connector Q (16P) No. 6 terminal and body ground.

Is there voltage?


YES - Repair the short to power in the wire between the under-dash fuse/relay box connector and the affected control unit.n


NO - Go to 17.


17.Turn the ignition switch OFF.

18.Reconnect the under-dash fuse/relay box connector Q (16P) and the gauge control module (tach) 36P connector.

19.Turn the ignition switch ON (II).

20.Clear the DTCs with the HDS.

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

22.Wait for 6 seconds or more.

Are DTCs B1000, B1008, B1011, and B1032 all indicated?


YES - Replace the gauge control module (tach).n


NO - Go to 23.


23.Turn the ignition switch OFF.

24.Reconnect the immobilizer-keyless control unit 7P connector.

25.Turn the ignition switch ON (II).

26.Clear the DTCs with the HDS.

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

28.Wait for 6 seconds or more.

Are DTCs B1000, B1008, B1011, and B1032 all indicated?


YES - Replace the immobilizer-keyless control unit.n


NO - Replace the  climate control unit.n