Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
DTC B1000: Communication Circuit Error (BUS-OFF)
- Clear the DTCs with the HDS.
- Turn the ignition switch to LOCK (0) and then back to ON (II).
- Wait for at least 6 seconds.
- 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.
- Turn the ignition switch to LOCK (0).
- Disconnect the appropriate connector at each control unit in the table.GAUGE CONTROL MODULE CHART
Unit Connector Gauge control module 32P connector Climate control unit 36P connector HandsFreeLink control unit 28P connector Immobilizer-keyless control unit 7P connector - Turn the ignition switch to ON (II).
- Clear the DTCs with the HDS.
- Turn the ignition switch to LOCK (0) and then back to ON (II).
- Wait for at least 6 seconds.
- Check for DTCs with the HDS.
Is DTC B1000 indicated?
YES -Go to step 12.
NO -Turn the ignition switch to LOCK (0), then go to step 15.
- Turn the ignition switch to LOCK (0).
- Disconnect the under-dash fuse/relay box connector Q(16P).
- Check for continuity between under-dash fuse/relay box connector Q (16P) terminal No. 3 and body ground.Fig 1: Checking Continuity Between Under-Dash Fuse/Relay Box Connector Q (16P) Terminal No. 3 And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Is there continuity?
YES -Repair a short to ground in the wire between the under-dash fuse/relay box connector and the affected control unit.
NO -Faulty MICU, replace the under-dash fuse/relay box.
- USA models (see REMOVAL AND INSTALLATION ).
- Canada models (see CANADA MODELS ).
- Reconnect the gauge control module 32P connector.
- Turn the ignition switch to ON (II).
- Clear the DTCs with the HDS.
- Turn the ignition switch to LOCK (0) and then back to ON (II).
- Wait for at least 6 seconds.
- Check for DTCs with the HDS.
Is DTC B1000 indicated?
YES -Replace the gauge control module (see GAUGE CONTROL MODULE REPLACEMENT ).
NO -Go to step 21.
- Reconnect the climate control unit 36P connector.
- Turn the ignition switch to ON (II).
- Clear the DTCs with the HDS.
- Turn the ignition switch to LOCK (0) and then back to ON (II).
- Wait for at least 6 seconds.
- Check for DTCs with the HDS.
Is DTC B1000 indicated?
YES -Replace the climate control unit (see CLIMATE CONTROL UNIT REMOVAL/INSTALLATION ).
NO -Go to step 27.
- Reconnect the HandsFreeLink control unit 28P connector.
- Turn the ignition switch to ON (II).
- Clear the DTCs with the HDS.
- Turn the ignition switch to LOCK (0) and then back to ON (II).
- Wait for at least 6 seconds.
- Check for DTCs with the HDS.
Is DTC B1000 Indicated?
YES -Replace the HandsFreeLink control unit (see CONTROL UNIT INPUT TEST/REPLACEMENT ).
NO -Replace the immobilizer-keyless control unit (see IMMOBILIZER-KEYLESS CONTROL UNIT REPLACEMENT ).
NO RELATED
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.