DTC U0122-00: Lost Communication With The VSA Modulator-Control Unit (Multi Purpose Camera Unit) (With ACC)

NOTE:  Before you troubleshoot, review the general troubleshooting information - Refer to: How to Troubleshoot the Adaptive Cruise Control (ACC) and How to Troubleshoot the Collision Mitigation Braking System (CMBS) .

1. CAN gateway system DTC check

   -1. Turn the vehicle to the ON mode.

   - 2. 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 indicated DTCs troubleshooting.

   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?

   VSA modulator-control unit (Bus A) is Not Available

   Go to step 3.

   VSA modulator-control unit (Bus B) is Not Available

   Go to step 4.

   Multipurpose camera unit (Bus A) is Not Available

   Go to step 5.

   Multipurpose camera unit and VSA modulator-control unit are Detected

   Intermittent failure, the system is OK at this time. Refer to intermittent failures troubleshooting - Refer to: How to Troubleshoot the Adaptive Cruise Control (ACC) or How to Troubleshoot the Collision Mitigation Braking System (CMBS) . If the freeze data/on-board snapshot of this DTC is recorded, try to reproduce the failure under the same conditions with the Freeze data/on-board snapshot.

3. Open wire check (F-CAN A_L, F-CAN A_H lines)

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

   - 2. Disconnect the following connectors.

   CAN gateway 24P connector

   VSA modulator-control unit 38P connector

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

   Test condition	Vehicle OFF (LOCK) mode
   	CAN gateway 24P connector: disconnected
   	VSA modulator-control unit 38P connector: disconnected
   Test point 1	CAN gateway 24P connector No. 15

   Test point 2

   VSA modulator-control unit 38P connector No. 26 - Refer to: VSA Modulator-Control Unit Connector for Inputs and Outputs (With Auto Idle Stop System) (2015-17) or VSA Modulator-Control Unit Connector for Inputs and Outputs (Without Auto Idle Stop System) (2015-17) or VSA Modulator-Control Unit Connector for Inputs and Outputs (2018-19)

   Test point 1	CAN gateway 24P connector No. 14
   Test point 2	VSA modulator-control unit 38P connector No. 38 - Refer to: VSA Modulator-Control Unit Connector for Inputs and Outputs (With Auto Idle Stop System) (2015-17) or VSA Modulator-Control Unit Connector for Inputs and Outputs (Without Auto Idle Stop System) (2015-17) or VSA Modulator-Control Unit Connector for Inputs and Outputs (2018-19)

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

   Is there continuity?

   YES 

   Check for loose terminals at the CAN gateway 24P connector and the VSA modulator-control unit 38P connector. If they are OK, update the VSA modulator-control unit if it does not have the latest software - Refer to: VSA Modulator-Control Unit Update (With SH-AWD) or VSA Modulator-Control Unit Update (Without SH-AWD) , then recheck. If the DTC U0122-00 goes away and the VSA modulator-control unit updated, troubleshooting is complete. If DTC U0122-00 is indicated after the VSA modulator-control unit updated, replace the VSA modulator-control unit - Refer to: VSA Modulator-Control Unit Removal and Installation (With SH-AWD) or VSA Modulator-Control Unit Removal and Installation (Without SH-AWD) .

   NO 

   Repair an open in the wire between the CAN gateway and the VSA modulator-control unit.

4. Open wire check (F-CAN B_L, F-CAN B_H lines)

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

   - 2. Disconnect the following connectors.

   CAN gateway 24P connector

   VSA modulator-control unit 38P connector

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

   Test condition	Vehicle OFF (LOCK) mode
   	CAN gateway 24P connector: disconnected
   	VSA modulator-control unit 38P connector: disconnected
   Test point 1	CAN gateway 24P connector No. 10
   Test point 2	VSA modulator-control unit 38P connector No. 20 - Refer to: VSA Modulator-Control Unit Connector for Inputs and Outputs (With Auto Idle Stop System) (2015-17) or VSA Modulator-Control Unit Connector for Inputs and Outputs (Without Auto Idle Stop System) (2015-17) or VSA Modulator-Control Unit Connector for Inputs and Outputs (2018-19)

   Test point 1	CAN gateway 24P connector No. 11
   Test point 2	VSA modulator-control unit 38P connector No. 31 - Refer to: VSA Modulator-Control Unit Connector for Inputs and Outputs (With Auto Idle Stop System) (2015-17) or VSA Modulator-Control Unit Connector for Inputs and Outputs (Without Auto Idle Stop System) (2015-17) or VSA Modulator-Control Unit Connector for Inputs and Outputs (2018-19)

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

   Is there continuity?

   YES 

   Check for loose terminals at the CAN gateway 24P connector and the VSA modulator-control unit 38P connector. If they are OK, update the VSA modulator-control unit if it does not have the latest software - Refer to: VSA Modulator-Control Unit Update (With SH-AWD) or VSA Modulator-Control Unit Update (Without SH-AWD) , then recheck. If the DTC U0122-00 goes away and the VSA modulator-control unit updated, troubleshooting is complete. If DTC U0122-00 is indicated after the VSA modulator-control unit updated, replace the VSA modulator-control unit - Refer to: VSA Modulator-Control Unit Removal and Installation (With SH-AWD) or VSA Modulator-Control Unit Removal and Installation (Without SH-AWD) .

   NO 

   Repair an open in the wire between the CAN gateway and the VSA modulator-control unit.

5. Open wire check (F-CAN A_L, F-CAN A_H lines)

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

   - 2. Disconnect the following connectors.

   CAN gateway 24P connector

   Multipurpose camera unit 20P connector

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

   Test condition	Vehicle OFF (LOCK) mode
   	CAN gateway 24P connector: disconnected
   	Multipurpose camera unit 20P connector: disconnected
   Test point 1	CAN gateway 24P connector No. 15
   Test point 2	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 1	CAN gateway 24P connector No. 14
   Test point 2	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)

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

   Is there continuity?

   YES 

   The F-CAN A_L and F-CAN A_H wires are OK. Go to step 6.

   NO 

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

6. Multipurpose camera unit check (update)

   -1. Reconnect the following connectors.

   CAN gateway 24P connector

   Multipurpose camera unit 20P connector

   - 2. Update the multipurpose camera unit if it does not have the latest software.

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

   - 4. Turn the vehicle to the ON mode, then wait for at least 5 seconds.

   - 5. Check for DTCs with the HDS.

   Is DTC U0122-00 indicated?

   YES 

   Check for loose terminals in the multipurpose camera unit 20P connector. If the multipurpose camera unit was updated and the symptom/indication is still present, replace the multipurpose camera unit .

   NO 

   Troubleshooting is complete. If any other DTCs are indicated, go to the indicated DTC's troubleshooting.