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Home >> Acura >> 2017 >> TLX SH-AWD >> Repair and Diagnosis (Single Page) >> Steering >> Electronic Steering >> Precision All Wheel Steering Control Unit - Diagnostics >> DTC Troubleshooting >> DTC U0122-00: F-CAN Malfunction (Precision All Wheel Steer Control Unit-VSA Modulator-Control Unit) (With ACC) (Precision All Wheel Steer Control Unit (With ACC)) (2015-17)
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DTC U0122-00: F-CAN Malfunction (Precision All Wheel Steer Control Unit-VSA Modulator-Control Unit) (With ACC) (Precision All Wheel Steer Control Unit (With ACC)) (2015-17)

NOTE: Before you troubleshoot, review the general troubleshooting information .

DTC Description DTC Freeze Frame
U0122-00 F-CAN Malfunction (Precision All Wheel Steer Control Unit-VSA Modulator-Control Unit)    

DTC (Precision all wheel steer)

  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 troubleshooting for CAN gateway system DTC (s).

    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. Refer to:  4

    Precision all wheel steer control unit is Not Available

    Go to step 5. Refer to:  5

    Precision all wheel steer control unit and VSA modulator-control unit are Detected

    Intermittent failure, the system is OK at this time. Refer to intermittent failures troubleshooting . 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)
    GHH203141Courtesy 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 was 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 VSA modulator-control unit and the CAN gateway.

  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)
    GHH203142Courtesy 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 was 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 VSA modulator-control unit and the CAN gateway.

  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
    Precision all wheel steer control unit connector A (16P)

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

    Test condition Vehicle OFF (LOCK) mode
      CAN gateway 24P connector: disconnected
      Precision all wheel steer control unit connector A (16P): disconnected
    Test point 1 CAN gateway 24P connector No. 15
    Test point 2 Precision all wheel steer control unit connector A (16P) No. 14 - Refer to: Precision All Wheel Steer Control Unit Connector for Inputs and Outputs (2015-17) or Precision All Wheel Steer Control Unit Connector for Inputs and Outputs (2018-19)
    Test point 1 CAN gateway 24P connector No. 14
    Test point 2 Precision all wheel steer control unit connector A (16P) No. 6 - Refer to: Precision All Wheel Steer Control Unit Connector for Inputs and Outputs (2015-17) or Precision All Wheel Steer Control Unit Connector for Inputs and Outputs (2018-19)
    GHH203143Courtesy 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 Precision all wheel steer control unit.

  6. Precision all wheel steer control unit check (update or substitution)

    -1. Reconnect the following connectors.

    CAN gateway 24P connector
    Precision all wheel steer control unit connector A (16P)

    - 2. Update the precision all wheel steer control unit if it does not have the latest software. If the unit already has the latest software, substitute a known-good precision all wheel steer control unit.

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

    - 4. Start the engine, and let it idle for at least 10 seconds.

    - 5. Check for DTCs with the HDS.

    DTC Description DTC Freeze Frame
    U0122-00 F-CAN Malfunction (Precision All Wheel Steer Control Unit-VSA Modulator-Control Unit)    

    Is DTC U0122-00 indicated?

    YES 

    Check for loose terminals and poor connections at the precision all wheel steer control unit. If the precision all wheel steer control unit was updated, substitute a known-good precision all wheel steer control unit , then retest. If the precision all wheel steer control unit was substituted, go to step 1.

    NO 

    If the precision all wheel steer control unit was updated, troubleshooting is complete. If the precision all wheel steer control unit was substituted, replace the original precision all wheel steer control unit .