DTC B1000: Communication Bus Line Error
- Clear the DTCs with the HDS.
- Turn the ignition switch to LOCK (0), and then back ON (II).
- Wait for 6 seconds or more.
- Check for DTCs with the HDS.
Is DTC B1000 indicated?
YES - Go to step 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 (see BATTERY TEST ) and the charging system.
- Check for DTCs with the HDS.
Are DTCs B1000, B1005, B1007, B1011, B1012, B1013, B1015 and B1032 all indicated?
YES - Go to step 6.
NO - Faulty MICU; replace the under-dash fuse/ relay box.
- Turn the ignition switch to LOCK (0).
- Disconnect the appropriate connector at each control unit in the table one at a time. Clear the DTC, then recheck for DTCs after each unit is disconnected.CONTROL UNIT CONNECTOR REFERENCE
Control unit Connector Relay control module Under-hood fuse/relay box connector E (14P) Gauge control module Connector A (12P) Immobilizer-keyless control unit 7P connector Combination switch control unit 8P connector Driver's MPCS unit Connector A (40P) Climate control unit 40P connector Audio unit Connector C (24P) HandsFreeLink control unit 28P connector Power seat control unit Connector A (40P) Power tailgate control unit Connector C(14P) AcuraLink control unit (XM receiver) Connector B(16P) Rear MICU(1) Rear fuse/relay box connector B (34P) (1) Disconnect this one last Is DTC B1000 indicated with each individual unit disconnected?
YES - Go to step 11.
NO - Replace the control unit that was disconnected when B1000 did not reset (If the unit is the rear MICU, go to step 8.)
- Disconnect rear fuse/relay box connectors B (34P) and C (42P).
- Check for continuity between each of the rear fuse/ relay box connector terminals listed in the table and body ground.REAR FUSE/ RELAY BOX CONNECTOR TERMINALS REFERENCE
Connected control unit Rear fuse/relay box connector terminal Power seat control unit B14 Power tailgate control unit C16 AcuraLink control unit (XM receiver) C32 Is there continuity?
YES - Repair short to ground in the wire between the rear fuse/relay box and the affected control unit.
NO - Go to step 10.
- Measure the voltage between each of the rear fuse/ relay box connector terminals listed in the table and body ground.REAR FUSE/ RELAY BOX CONNECTOR TERMINALS REFERENCE
Connected control unit Rear fuse/relay box connector terminal Power seat control unit B14 Power tailgate control unit C16 Acura Link control unit (XM receiver) C32 Is there less than 1 V?
YES - Replace the rear fuse/relay box.
NO - Repair short to power in the wire between the rear fuse/ relay box and the affected control unit.
- Disconnect each control unit connectors in the table.CONTROL UNIT CONNECTOR REFERENCE
Control unit Connector Relay control module Under-hood fuse/relay box connector E (14P) Gauge control module Connector A (12P) Immobilizer-keyless control unit 7P connector Combination switch control unit 8P connector Driver's MPCS unit Connector A (40P) Climate control unit 40P connector Audio unit Connector C (24P) HandsFreeLink control unit 28P connector - Check for continuity between the under-dash fuse/ relay box connector N (45P) No. 22 terminal and body ground.Fig 1: Identifying Continuity Between Under-Dash Fuse/ Relay Box Connector N (45P) No. 22 Terminal And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Is there continuity?
YES - Repair short to ground in the wire.
NO - Go to step 13.
- Turn the ignition switch ON (II).
- Measure the voltage between the under-dash fuse/ relay box connector N (45P) No. 22 terminal and body ground.Fig 2: Measuring Voltage Between Under-Dash Fuse/ Relay Box Connector N (45P) No. 22 Terminal And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Is there battery voltage?
YES - Repair short to power in the wire.
NO - Faulty MICU, replace the under-dash fuse/ relay box.