DTC U0122-00: Lost Communication With the VSA Modulator-Control Unit (Adaptive Cruise Control Unit) (2015)

NOTE:  Before you troubleshoot, record all freeze data and any on-board snapshot, and review the how to troubleshoot information - Refer to: How to Troubleshoot the Adaptive Cruise Control (ACC) (2014-15) .

DTC (ACC)

1. CAN gateway DTC check

   -1. Turn the vehicle to the ON mode.

   - 2. Check for 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
   U0056-00 CAN Gateway F-CAN ch C Bus Off
   U3000-49 Gateway Internal Failure

   DTC (CAN gateway)

   Is DTC U0029-00, U0047-00, U0056-00, and/or U3000-49 indicated?

   YES 

   Go to the indicated DTC's 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.

   Which result is indicated?

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

   Go to step 3.

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

   Go to step 4.

   ACC unit (Bus B) is Not Available

   Go to step 5.

   ACC unit (Bus C) is Not Available

   Go to step 6.

   VSA modulator-control unit and ACC unit are Detect

   Intermittent failure, the system is OK at this time.

3. 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 - Refer to: CAN Gateway Removal and Installation (2014-15)

   VSA modulator-control unit 21P 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 21P connector: disconnected

   Test circuit	F-CAN B_L
   Test point 1	CAN gateway 24P connector No. 10 (LT GRN)
   Test point 2	VSA modulator-control unit 21P connector No. 15 (LT GRN)

   Test circuit	F-CAN B_H
   Test point 1	CAN gateway 24P connector No. 11 (GRN)
   Test point 2	VSA modulator-control unit 21P connector No. 8 (LT BLU)

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

   Is there continuity?

   YES 

   The F-CAN B_L and F-CAN B_H wires are OK. Check for poor connections or loose terminals at the CAN gateway and the VSA modulator-control unit, and recheck. If the DTC is still indicated, replace the VSA modulator-control unit .

   NO 

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

4. Open wire check (F-CAN C_L, F-CAN C_H lines)

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

   - 2. Disconnect the following connectors.

   CAN gateway 24P connector - Refer to: CAN Gateway Removal and Installation (2014-15)

   VSA modulator-control unit 21P 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 21P connector: disconnected
   Test circuit	F-CAN C_L
   Test point 1	CAN gateway 24P connector No. 8 (PUR)
   Test point 2	VSA modulator-control unit 21P connector No. 16 (PUR)

   Test circuit	F-CAN C_H
   Test point 1	CAN gateway 24P connector No. 9 (TAN)
   Test point 2	VSA modulator-control unit 21P connector No. 9 (ORN)

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

   Is there continuity?

   YES 

   The F-CAN C_L and F-CAN C_H wires are OK. Check for poor connections or loose terminals at the CAN gateway and the VSA modulator-control unit, and recheck. If the DTC is still indicated, replace the VSA modulator-control unit .

   NO 

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

5. 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 - Refer to: CAN Gateway Removal and Installation (2014-15)

   ACC unit 20P connector

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

   Test condition	Vehicle OFF (LOCK) mode
   	CAN gateway 24P connector: disconnected
   	ACC unit 20P connector: disconnected
   Test circuit	F-CAN B_L
   Test point 1	CAN gateway 24P connector No. 10 (LT GRN)
   Test point 2	ACC unit 20P connector No. 13 (LT GRN)

   Test circuit	F-CAN B_H
   Test point 1	CAN gateway 24P connector No. 11 (GRN)
   Test point 2	ACC unit 20P connector No. 2 (GRN)

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

   Is there continuity?

   YES 

   The F-CAN B_L and F-CAN B_H wires are OK. Check for poor connections or loose terminals at the CAN gateway and the ACC unit, and recheck. If the DTC is still indicated, replace the ACC unit .

   NO 

   Repair an open in F-CAN B_L or F-CAN B_H wire between the CAN gateway and the ACC unit.

6. Open wire check (F-CAN C_L, F-CAN C_H lines)

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

   - 2. Disconnect the following connectors.

   CAN gateway 24P connector - Refer to: CAN Gateway Removal and Installation (2014-15)

   ACC unit 20P connector

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

   Test condition	Vehicle OFF (LOCK) mode
   	CAN gateway 24P connector: disconnected
   	ACC unit 20P connector: disconnected
   Test circuit	F-CAN C_L
   Test point 1	CAN gateway 24P connector No. 8 (PUR)
   Test point 2	ACC unit 20P connector No. 15 (PUR)

   Test circuit	F-CAN C_H
   Test point 1	CAN gateway 24P connector No. 9 (TAN)
   Test point 2	ACC unit 20P connector No. 4 (TAN)

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

   Is there continuity?

   YES 

   The F-CAN C_L and F-CAN C_H wires are OK. Check for poor connections or loose terminals at the CAN gateway and the ACC unit, and recheck. If the DTC is still indicated, replace the ACC unit .

   NO 

   Repair an open in F-CAN C_L or F-CAN C_H wire between the CAN gateway and the ACC unit.