Honda HR-V: DTC U1280 (MICU) B-CAN Communication Bus Line Error (BUS-OFF)
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DTC (MICU)
NOTE : If you are troubleshooting multiple DTCs, be sure to follow the
instructions in B-CAN System
Diagnosis Test Mode A - Refer to: Body Electrical Troubleshooting - B-CAN System
Diagnosis Test Mode
A - Initial Communication and DTC Checks.
1. Problem verification:
- Clear the DTCs with the HDS.
Clear DTCs
- Turn the vehicle to the OFF (LOCK) mode and then the ON mode.
- Wait for at least 6 seconds.
- Check for DTCs with the HDS.
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Is DTC U1280 indicated?
YES
Go to step 2.
NO
Intermittent failure, the system is OK at this time. Check for loose or poor
connections.
2. B-CAN related units check:
- Turn the vehicle to the OFF (LOCK) mode.
- 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.
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Clear DTCs
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Is DTC U1280 indicated with each individual unit disconnected?
YES
Leave the connectors disconnected, and go to step 3.
NO
Replace the control unit that was disconnected when DTC U1280 did not reset.
3. Shorted wire check (B-CAN lines) 1:
- Turn the vehicle to the OFF (LOCK) mode.
- Disconnect the following connectors.
Under-dash fuse/relay box connector D (24P) Under-dash fuse/relay box
connector H (20P)
- Check for continuity between test points 1 and 2.
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Is there continuity?
YES
Repair a short to ground in the B-CAN wires.
NO
Go to step 4.
4. Shorted wire check (B-CAN lines) 2:
- Check for continuity between test points 1 and 2.
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Is there continuity?
YES
Repair a short to ground in the B-CAN wires.
NO
Go to step 5.
5. Shorted wire check (B-CAN_L to B-CAN_H line) 1:
- Check for continuity between test points 1 and 2.
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Is there continuity?
YES
Repair a short in the B-CAN_L to B-CAN_H wire.
NO
Go to step 6.
6. Shorted wire check (B-CAN_L to B-CAN_H line) 2:
- Check for continuity between test points 1 and 2.
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Is there continuity?
YES
Repair a short in the B-CAN_L to B-CAN_H wire.
NO
The B-CAN_L to B-CAN_H wire is OK. Faulty MICU; replace the under-dash
fuse/relay box.
READ NEXT:
NOTE : The DTC may be stored due to the grounding failure or the power source
failure at the transmitting
control unit (the grounding inspection and the power source inspection on each
control unit
NOTE :
Before you troubleshoot, review the how to troubleshoot information -
Refer to: How to Troubleshoot
the Forward Collision Warning (FCW), or How to Troubleshoot the Lane
Departure Warning
SEE MORE:
NOTE: Before you troubleshoot, review the how to troubleshoot the
electric parking brake system.
1. Problem verification:
Turn the vehicle to the ON mode.
Clear the DTC with the HDS.
Turn the vehicle to the OFF (LOCK) mode, then to the ON mode.
Pull the electric parking brake switch to apply
NOTE:
Check the vehicle 12 volt battery condition first.
Check for B-CAN DTCs and resolve them before troubleshooting.
Before doing this troubleshooting, make sure whether a parking brake is
working properly and the electric parking brake indicator in the gauge
control module is being lit.