DTC U1280: Communication Bus Line Error (BUS-OFF)

WARNING: This page does not describe the selected car, but rather 7 other vehicles, including the 2017 Honda Odyssey, 2016 Honda Odyssey, 2015 Honda Odyssey, 2014 Honda Odyssey, and 2013 Honda Odyssey. However, it is still accessible from the selected car via links, so may be relevant.

NOTE: If you are troubleshooting multiple DTCs, be sure to follow the instructions in B-CAN System Diagnosis Test Mode A (see TROUBLESHOOTING - B-CAN SYSTEM DIAGNOSIS TEST MODE A ).

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 U1280 indicated?

YES -Go to step 5.

NO -Intermittent failure, the system 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 (see SYMPTOM TROUBLESHOOTING INDEX ).
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.

CONNECTOR TERMINAL REFERENCE CHART

Control Unit

Connector

Rear MICU

Connector B (36P)

Power window master switch

37P connector

Gauge control module

32P connector

Immobilizer-keyless control unit

7P connector

Climate control unit⁽¹⁾ or HVAC control unit⁽²⁾

Connector A (28P)

Relay control module

Connector B(16P)

Navigation display unit⁽³⁾

32P connector

Navigation unit⁽³⁾

Connector D (20P)

Audio-display USB adapter control unit⁽⁴⁾

Connector A (32P)

Audio unit⁽⁵⁾

Connector D (20P)

Power seat control unit⁽⁶⁾

Connector B (40P)

Left power sliding door control unit⁽⁷⁾

Connector B(16P)

Right power sliding door control unit⁽⁷⁾

Connector B(16P)

Parking and back-up sensor control unit⁽⁸⁾

24P connector

Power tailgate control unit⁽⁹⁾

Connector C(14P)

Headlight leveling control unit⁽¹⁰⁾

16P connector

Seat heater control unit⁽¹¹⁾

14P connector

BSI control unit⁽¹²⁾

16P connector

⁽¹⁾	With climate control

⁽²⁾	Without climate control

⁽³⁾	With navigation

⁽⁴⁾	Without navigation and with USB adapter

⁽⁵⁾	With 3 line type

⁽⁶⁾

With DPMS

⁽⁷⁾	With sliding door

⁽⁸⁾	With parking and back-up system

⁽⁹⁾	With power tailgate

⁽¹⁰⁾

With HID

⁽¹¹⁾	With seat heater

⁽¹²⁾

With BSI

Is DTC U1280 indicated with each individual unit disconnected?

YES -Leave the connectors disconnected, and go to step 7.

NO -Go to the input test for the control unit that was disconnected when DTC U1280 did not reset, and perform all power and ground input tests. If the tests prove OK, replace that unit.

Rear MICU input test (see REAR MICU ).
Door multiplex control unit (power window master switch) input test (see POWER WINDOW MASTER SWITCH INPUT TEST ).
Gauge control module input test (see GAUGE CONTROL MODULE INPUT TEST ).
Immobilizer-keyless control unit input test (see IMMOBILIZER-KEYLESS CONTROL UNIT INPUT TEST ).
Climate control unit power and ground circuit troubleshooting (see CLIMATE CONTROL UNIT POWER AND GROUND CIRCUIT TROUBLESHOOTING ).
HVAC control unit power and ground circuit troubleshooting (see HVAC CONTROL POWER AND GROUND CIRCUIT TROUBLESHOOTING ).
Power seat control unit input test (see POWER SEAT CONTROL UNIT INPUT TEST/REPLACEMENT ).
Navigation unit input test (see SYSTEM DESCRIPTION ).
Audio unit input test (see SYSTEM DESCRIPTION ).
Left power sliding door control unit input test (see CONTROL UNIT INPUT TEST ).
Right power sliding door control unit input test (see CONTROL UNIT INPUT TEST ).
Power tailgate control unit input test (see CONTROL UNIT INPUT TEST/REPLACEMENT ).
Parking and back-up sensor control unit input test (see PARKING AND BACK-UP SENSOR CONTROL UNIT INPUT TEST/REPLACEMENT ).
Seat heater control unit input test (see SEAT HEATER CONTROL UNIT INPUT TEST/REPLACEMENT ).
BSI control unit input test (see SYSTEM DESCRIPTION ).

Turn the ignition switch to LOCK (0).
Remove the driver's kick panel (see TRIM REMOVAL/INSTALLATION - DOOR AREAS ).
Disconnect these items:
- Driver's under-dash fuse/relay box connector E (44P)
- Driver's under-dash fuse/relay box connector G(16P)
- Driver's under-dash fuse/relay box connector H (13P)
Check for continuity between driver's under-dash fuse/relay box connector E (44P) terminals No. 31, No. 32, then between terminals No. 43, and No. 44 respectively.

Fig 1: Checking Continuity Between Driver's Under-Dash Fuse/Relay Box Connector Terminals No. 31 And No. 32
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES -Repair a short in the B-CAN wires.

NO -Go to step 11.
Check for continuity between driver's under-dash fuse/relay box connector G (16P) terminals No. 1 and No. 2.

Fig 2: Checking Continuity Between Driver's Under-Dash Fuse/Relay Box Connector Terminals No. 1 And No. 2
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES -Repair a short in the B-CAN wires.

NO -Go to step 12.
Check for continuity between driver's under-dash fuse/relay box connector H (13P) terminals No. 5 and No. 10.

Fig 3: Checking Continuity Between Driver's Under-Dash Fuse/Relay Box Connector Terminals No. 5 And No. 10
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES -Repair a short in the B-CAN wires.

NO -Go to step 13.
Check for continuity between body ground and driver's under-dash fuse/relay box connector H (44P) terminals No. 31, No. 32, No. 43, and No. 44 individually.

Fig 4: Checking Continuity Between Body Ground And Driver'S Under-Dash Fuse/Relay Box Connector Terminals
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES -Repair a short to ground in the B-CAN wires.

NO -Go to step 14.
Check for continuity between body ground and driver's under-dash fuse/relay box connector G (16P) terminals No. 1 and No. 2 individually.

Fig 5: Checking Continuity Between Body Ground And Driver's Under-Dash Fuse/Relay Box Connector Terminals No. 1 And No. 2
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES -Repair a short to ground in the B-CAN wires.

NO -Go to step 15.
Check for continuity between body ground and driver's under-dash fuse/relay box connector H (13P) terminals No. 5 and No. 10 individually.

Fig 6: Checking Continuity Between Body Ground And Driver'S Under-Dash Fuse/Relay Box Connector Terminals No. 5 And No. 10
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES -Repair a short to ground in the B-CAN wires.

NO -Go to step 16.
Turn the ignition switch to ON (II).
Measure the voltage between body ground and driver's under-dash fuse/relay box connector E (44P) terminals No. 31, No. 32, No. 43, and No. 44 individually.

Fig 7: Measuring Voltage Between Body Ground And Driver's Under-Dash Fuse/Relay Box Connector E (44P) Terminals
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there voltage?

YES -Repair a short to power in the B-CAN wires.

NO -Go to step 18.
Measure the voltage between body ground and driver's under-dash fuse/relay box connector G (16P) terminals No. 1 and No. 2 individually.

Fig 8: Measuring Voltage Between Body Ground And Driver's Under-Dash Fuse/Relay Box Connector G (16P) Terminals
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there voltage?

YES -Repair a short to power in the B-CAN wires.

NO -Go to step 19.
Measure the voltage between body ground and driver's under-dash fuse/relay box connector H (13P) terminals No. 5 and No. 10 individually.

Fig 9: Measuring Voltage Between Body Ground And Driver's Under-Dash Fuse/Relay Box Connector H (13P) Terminals
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there voltage?

YES -Repair a short to power in the B-CAN wires.

NO -Faulty MICU; replace the driver's under-dash fuse/relay box, USA models (see DRIVER'S UNDER-DASH FUSE/RELAY BOX (MICU) REMOVAL AND INSTALLATION ), Canada models (see CANADA MODELS ).