DTC U0104: Gauge Control Module Lost Communication with ACC Unit/Multipurpose Camera Unit (V6, Gauge Control Module with CAN gateway) (2015-17)

DTC (Gauge Control Module)

NOTE:  Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information - Refer to: How to Troubleshoot the Fuel and Emissions Systems (L4), or How to Troubleshoot the Dual Clutch Transmission (DCT), or How to Troubleshoot the Brake Booster Pressure Monitoring System (With Auto Idle Stop System), or How to Troubleshoot the Fuel and Emissions Systems (V6, Without Auto Idle Stop System), or How to Troubleshoot the Fuel and Emissions Systems (V6, With Auto Idle Stop System) .

1. CAN gateway system DTC check

   -1. Check for CAN gateway system DTCs with the HDS.

   DTC Description	DTC
   U0029-00 CAN Gateway F-CAN ch A Bus Off
   U0047-00 CAN Gateway F-CAN ch B Bus Off
   U3000-49 CAN Gateway Internal Failure

   Is DTC U0029-00, U0047-00, and/or U3000-49 indicated?

   YES 

   Go to the troubleshooting for CAN gateway system DTC (s) - Refer to: Communication Systems DTC Troubleshooting Index (V6, With CAN gateway) (2015-17) or Communication Systems DTC Troubleshooting Index (2018-19) .

   NO 

   Go to step 2.

2. F-CAN circuit communication check

   -1. Select the FUNCTION TEST in the CAN gateway with the HDS, then select the F-CAN Bus Connected Unit Check.

   F-CAN Bus Connected Unit Check

   Which result is indicated?

   GAUGE CONTROL MODULE (Bus A) is Not Available

   Go to step 3.

   ACC UNIT/MULTIPURPOSE CAMERA UNIT (Bus A) is Not Available

   Go to step 5. Refer to:  5

   GAUGE CONTROL MODULE and ACC UNIT/MULTIPURPOSE CAMERA UNIT are Detected

   Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the gauge control module, the CAN gateway, and the Multipurpose camera unit.

3. Open wire check (F-CAN A_H line)

   -1. Turn the vehicle to the OFF (LOCK) mode.

   - 2. Disconnect the following connectors.

   Gauge control module 32P connector

   CAN gateway 24P connector

   - 3. Check for continuity between test points 1 and 2.

   Test condition	Vehicle OFF (LOCK) mode
   	Gauge control module 32P connector: disconnected
   	CAN gateway 24P connector: disconnected
   Test point 1	Gauge control module 32P connector No. 27 - Refer to: Gauge Control Module Input Test (2015-17), or Gauge Control Module Input Test (2018-19)
   Test point 2	CAN gateway 24P connector No. 14

   Courtesy of HONDA, U.S.A., INC.

   Is there continuity?

   YES 

   The F-CAN A_H wire is OK. Go to step 4.

   NO 

   Repair an open in the F-CAN A_H wire between the gauge control module and the CAN gateway.

4. Open wire check (F-CAN A_L line)

   -1. Check for continuity between test points 1 and 2.

   Test condition	Vehicle OFF (LOCK) mode
   	Gauge control module 32P connector: disconnected
   	CAN gateway 24P connector: disconnected
   Test point 1	Gauge control module 32P connector No. 28 - Refer to: Gauge Control Module Input Test (2015-17), or Gauge Control Module Input Test (2018-19)
   Test point 2	CAN gateway 24P connector No. 15

   Courtesy of HONDA, U.S.A., INC.

   Is there continuity?

   YES 

   The F-CAN A_L wire is OK. Check for poor connections or loose terminals at the CAN gateway and the gauge control module. Substitute a known-good gauge control module , then recheck. If DTC U0104 is not indicated the gauge control module was substituted, replace the original gauge control module .

   NO 

   Repair an open in the F-CAN A_L wire between the gauge control module and the CAN gateway.

5. Open wire check (F-CAN A_H line)

   -1. Turn the vehicle to the OFF (LOCK) mode.

   - 2. Disconnect the following connectors.

   Multipurpose camera unit 20P connector

   CAN gateway 24P connector

   - 3. Check for continuity between test points 1 and 2.

   Test condition	Vehicle OFF (LOCK) mode
   	Multipurpose camera unit 20P connector: disconnected
   	CAN gateway 24P connector: disconnected
   Test point 1	Multipurpose camera unit 20P connector No. 2 - Refer to: Multipurpose Camera Unit Connector for Inputs and Outputs (2015-17) or Multipurpose Camera Unit Connector for Inputs and Outputs (2018-19)
   Test point 2	CAN gateway 24P connector No. 14

   Courtesy of HONDA, U.S.A., INC.

   Is there continuity?

   YES 

   The F-CAN A_H wire is OK. Go to step 6.

   NO 

   Repair an open in the F-CAN A_H wire between the multipurpose camera unit and the CAN gateway.

6. Open wire check (F-CAN A_L line)

   -1. Check for continuity between test points 1 and 2.

   Test condition	Vehicle OFF (LOCK) mode
   	Multipurpose camera unit 20P connector: disconnected
   	CAN gateway 24P connector: disconnected
   Test point 1	Multipurpose camera unit 20P connector No. 13 - Refer to: Multipurpose Camera Unit Connector for Inputs and Outputs (2015-17) or Multipurpose Camera Unit Connector for Inputs and Outputs (2018-19)
   Test point 2	CAN gateway 24P connector No. 15

   Courtesy of HONDA, U.S.A., INC.

   Is there continuity?

   YES 

   The F-CAN A_L wire is OK. Check for poor connections or loose terminals at the CAN gateway and the multipurpose camera unit. Update the multipurpose camera unit if it does not have the latest software, or substitute a known-good multipurpose camera unit , then recheck. If DTC U0104 goes away and the multipurpose camera unit was updated, troubleshooting is complete. If DTC U0104 goes away and the multipurpose camera unit was substituted, replace the original multipurpose camera unit .

   NO 

   Repair an open in the F-CAN A_L wire between the multipurpose camera unit and the CAN gateway.