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:
Removal
NOTE: Keep all foreign particles out of the transmission.
1. Vehicle - Lift
2. Engine Undercover - Remove (With 2WD)
3. Left Front Splash Shield - Remove
4. Engine - Warm Up
Start the engine, and warm it up to normal operating temperature (the
radiator fan comes on twice).
Turn the engi
DRIVESHAFT INSPECTION
Inspection
1. Driveshaft - Inspect
Check the inboard boot (A) and the outboard boot (B) on the driveshaft
(C) for
cracks, damage, leaking grease, and loose boot bands (D). If any damage is
found,
replace the boot and the boot bands
Check the driveshaft for cracks and