DTC U0122-00: F-CAN Malfunction (Electric Servo Brake Control Unit Lost Communication With VSA Modulator-control Unit) (Electric Servo Brake Control Unit) (2015)

DTCs (ESB)

1. Problem verification

   -1. Turn the vehicle to the ON mode.

   - 2. Clear the DTCs with the HDS.

   - 3. Turn the vehicle to the OFF (LOCK) mode, and then back to the ON mode.

   - 4. Check for DTCs with the HDS.

   DTC Description	DTC
   U0122-00 F-CAN Malfunction (Electric Servo Brake Control Unit Lost Communication With VSA Modulator-control Unit)

   Is DTC U0122-00 indicated?

   YES 

   The failure is duplicated. Go to step 2.

   NO 

   Intermittent failure, the system is OK at this time.

2. CAN gateway system DTC check

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

   DTC Description	DTC
   U0029-00 F-CAN A Malfunction (BUS-OFF)
   U0047-00 F-CAN B Malfunction (BUS OFF)
   U0056-00 F-CAN C Malfunction (BUS-OFF)
   U3000-49 CAN Gateway Internal Electronic Failure

   DTC (CAN GATEWAY)

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

   YES 

   Go to the troubleshooting for CAN gateway system DTC (s) - Refer to: How to Troubleshoot the Fuel and Emissions Systems (2014-15) .

   NO 

   Go to step 3.

3. 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?

   Electric servo brake control unit and VSA modulator-control unit are Detect

   Intermittent failure, the system is OK at this time.

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

   Go to step 4.

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

   Go to step 5.

   Electric servo brake control unit (Bus B) is Not Available

   Go to step 6.

4. Open wire check (F-CAN B_L, F-CAN B_H lines) 1

   -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. Update the VSA modulator-control unit if it does not have the latest software, then recheck. If the DTC U0122 goes away and the VSA modulator-control unit was updated, troubleshooting is complete. If the DTC U0122 goes away and the VSA modulator-control unit was substituted, replace the original VSA modulator-control unit .

   NO 

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

5. 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. Update the VSA modulator-control unit if it does not have the latest software, then recheck. If the DTC U0122 goes away and the VSA modulator-control unit was updated, troubleshooting is complete. If the DTC U0122 goes away and the VSA modulator-control unit was substituted, replace the original VSA modulator-control unit .

   NO 

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

6. Open wire check (F-CAN B_L, F-CAN B_H lines) 2

   -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)

   Electric servo brake control unit connector A (11P) - Refer to: Electric Servo Brake Control Unit Removal and Installation (2014-15)

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

   Test condition	Vehicle OFF (LOCK) mode
   	CAN gateway 24P connector: disconnected
   	Electric servo brake control unit connector A (11P): disconnected
   Test circuit	F-CAN B_L
   Test point 1	CAN gateway 24P connector No. 10 (LT GRN)
   Test point 2	Electric servo brake control unit connector A (11P) No. 11 (LT GRN)

   Test circuit	F-CAN B_H
   Test point 1	CAN gateway 24P connector No. 11 (GRN)
   Test point 2	Electric servo brake control unit connector A (11P) No. 10 (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. Replace the electric servo brake control unit - Refer to: Electric Servo Brake Control Unit Removal and Installation (2014-15) .

   NO 

   Repair an open in the wire between the CAN gateway and the electric servo brake control unit.