Body Electrical Troubleshooting - B-CAN System Diagnosis Test Mode A - Initial Communication and DTC Checks

WARNING: This page is about a different car, the 2022 Honda Accord, 2021 Honda Accord, 2020 Honda Accord, 2019 Honda Accord, and 2018 Honda Accord. However, it is still accessible from the selected car via links, so may be relevant.

Check the PCM for DTCs and troubleshoot PCM or F-CAN loss of communication errors first, then do this diagnosis if the symptom is related to the B-CAN system.

Compare the symptom with this list of B-CAN related systems:

Gauge control module
Head up display
Exterior lights
Turn signals
Entry light control
Safety indicators
Horns (security and panic)
Reminder chimes (seat belt, lights-on, and parking brake etc.)
Power window/moonroof timer
Wiper/washer
Security
Keyless entry
Power door locks
Immobilizer
Driving position memory system
Keyless access control
Climate control
Ventilated seat
Seat heater
Wireless charger
Audio and visual system
Telematics system
Driving support
BSI system

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If the symptom is related to the B-CAN, go to step 2.
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If the symptom is not related to the B-CAN, go to the system symptom troubleshooting.

2. Connect the HDS to the data link connector (DLC) .From the BODY ELECTRICAL SYSTEM SELECT menu, select B-CAN CONTROL UNITS INFORMATION, and then select CHECK CONNECTED CONTROL UNITS listed to see if the following control units are communicating with the HDS.

Body control module
Gauge control module
Head up display
Climate control unit
Automatic lighting control unit-sensor
Power window master switch
Power seat control unit
Relay control module
Front seat heater control unit
Ventilated seat control unit
Wireless charger
Audio unit
Audio-navigation unit
Telematics control unit
Left side BSI radar unit
Right side BSI radar unit

NOTE:

If a unit is communicating with the HDS, "DETECT" is displayed.
If a unit is not communicating or the vehicle is not equipped, "NOT AVAILABLE" is displayed.
The HDS only checks the status one time when BODY ELECTRICAL is selected. To recheck the status after repair, reboot the HDS.

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If all control units are communicating with the HDS, go to step 4.
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If any of the control units are not communicating, go to B-CAN System Diagnosis Test Mode B .
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If all units are not communicating or only the body control module is communicating, go to body control module DTC U1280 troubleshooting .

4. Select the system that has the problem from the BODY ELECTRICAL SYSTEM SELECT menu, then select DTCs.

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If any DTCs are indicated, go to step 5.

Record all DTCs, and sort them by DTC type, then troubleshoot them in this order:

Internal error DTCs.
Loss of communication DTCs.
Signal error DTCs.