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DTC U0122: Power Control Unit Lost Communication With VSA Modulator-Control Unit (VSA Message) (Keyless Access Power Control Unit) (2016-17)

WARNING: This page is about a different variant/trim than selected.
DTC Description DTC
U0122 Power Control Unit Lost Communication with VSA Modulator-Control Unit (VSA Message)  

DTC (Power Control Unit)

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 (V6), or How to Troubleshoot the Fuel and Emissions Systems (L4), or How to Troubleshoot the A/T System (A/T) (2013-15), or How to Troubleshoot the CVT System (CVT) (2013-15), or How to Troubleshoot the A/T System (A/T) (2016-17), or How to Troubleshoot the CVT System (CVT) (2016-17) .
  1. Problem verification

    -1. Clear the DTCs with the HDS.

    - 2. Press the engine start/stop button to select the OFF mode and then the ON mode.

    - 3. Wait for at least 6 seconds.

    - 4. Check for DTCs with the HDS.

    DTC Description DTC
    U0122 Power Control Unit Lost Communication with VSA Modulator-Control Unit (VSA Message)  

    Is DTC U0122 indicated?

    YES 

    Go to step 2 below.

    NO 

    Intermittent failure, the system is OK at this time. Check for loose or poor connections.

  2. Fuse check

    -1. Check the following fuse.

    Fuse No. B10 (7.5 A)
    Location Under-dash fuse/relay box

    Is the fuse OK?

    YES 

    Go to step 3 below.

    YES 

    Go to step  6

    NO 

    Replace the fuse. If the fuse blows again, repair a short to ground in the No. B10 (7.5 A) fuse circuit.

  3. Open wire check (IG1 VSA/ABS line)

    -1. Press the engine start/stop button to select the OFF mode.

    - 2. Disconnect the following connector.

    VSA modulator-control unit 22P connector - Refer to: VSA Modulator-Control Unit Removal and Installation, or VSA Modulator-Control Unit Removal and Installation (With ACC) (2016-17)

    - 3. Press the engine start/stop button to select the ON mode.

    - 4. Measure the voltage between test points 1 and 2.

    Test condition ON mode
    VSA modulator-control unit 21P connector: disconnected
    Test circuit IG1 VSA/ABS
    Test point 1 VSA modulator-control unit 21P connector No. 6 (YEL)
    Test point 2 Body ground
    GHH62329Courtesy of HONDA, U.S.A., INC.

    Is there battery voltage?

    YES 

    The IG1 VSA/ABS wire is OK. Go to step 4 below.

    NO 

    Repair an open or high resistance in the wire.

  4. Open wire check (GND line)

    -1. Press the engine start/stop button to select the OFF mode.

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

    Test condition OFF mode
    VSA modulator-control unit 21P connector: disconnected
    Test circuit GND
    Test point 1 VSA modulator-control unit 21P connector No. 1 (BLK)
    Test point 2 Body ground
    Test circuit GND
    Test point 1 VSA modulator-control unit 21P connector No. 2 (BLK)
    Test point 2 Body ground
    GHH62330Courtesy of HONDA, U.S.A., INC.

    Is there continuity?

    YES 

    The GND wires are OK. Go to step 5 below.

    NO 

    Repair an open or high resistance in the ground wire or poor ground (G202).

  5. Open wire check (F-CAN lines)

    -1. Disconnect the following connector.

    Keyless access control unit connector C (24P)

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

    Test condition OFF mode
    VSA modulator-control unit 21P connector: disconnected
    Keyless access control unit connector C (24P) : disconnected
    Test circuit F-CAN_H
    Test point 1 VSA modulator-control unit 21P connector No. 8 (WHT)
    Test point 2 Keyless access control unit connector C (24P) No. 4 (WHT)
    Test circuit F-CAN_L
    Test point 1 VSA modulator-control unit 21P connector No. 15 (RED)
    Test point 2 Keyless access control unit connector C (24P) No. 5 (RED)
    GHH62331Courtesy of HONDA, U.S.A., INC.

    Is there continuity?

    YES 

    The F-CAN wires are OK. Replace the keyless access control unit .

    NO 

    An open or poor connection in the F-CAN wires between the VSA modulator-control unit and the keyless access control unit.

  6. Open wire check (IG1 VSA/ABS line)

    -1. Press the engine start/stop button to select the OFF mode.

    - 2. Disconnect the following connector.

    VSA modulator-control unit 38P connector - Refer to: VSA Modulator-Control Unit Removal and Installation, or VSA Modulator-Control Unit Removal and Installation (With ACC) (2016-17)

    - 3. Press the engine start/stop button to select the ON mode.

    - 4. Measure the voltage between test points 1 and 2.

    Test condition ON mode
    VSA modulator-control unit 38P connector: disconnected
    Test circuit IG1 VSA/ABS
    Test point 1 VSA modulator-control unit 38P connector No. 36 (YEL)
    Test point 2 Body ground
    GHH62332Courtesy of HONDA, U.S.A., INC.

    Is there battery voltage?

    YES 

    The IG1 VSA/ABS wire is OK. Go to step 7 below.

    NO 

    Repair an open or high resistance in the wire.

  7. Open wire check (GND line)

    -1. Press the engine start/stop button to select the OFF mode.

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

    Test condition OFF mode
    VSA modulator-control unit 38P connector: disconnected
    Test circuit GND
    Test point 1 VSA modulator-control unit 38P connector No. 1 (BLK)
    Test point 2 Body ground
    Test circuit GND
    Test point 1 VSA modulator-control unit 38P connector No. 3 (BLK)
    Test point 2 Body ground
    GHH62333Courtesy of HONDA, U.S.A., INC.

    Is there continuity?

    YES 

    The GND wires are OK. Go to step 8 below.

    NO 

    Repair an open or high resistance in the ground wire or poor ground (G202).

  8. Open wire check (F-CAN lines)

    -1. Disconnect the following connector.

    Keyless access control unit connector C (24P)

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

    Test condition OFF mode
    VSA modulator-control unit 38P connector: disconnected
    Keyless access control unit connector C (24P) : disconnected
    Test circuit F-CAN_H
    Test point 1 VSA modulator-control unit 38P connector No. 38 (WHT)
    Test point 2 Keyless access control unit connector C (24P) No. 4 (WHT)
    Test circuit F-CAN_L
    Test point 1 VSA modulator-control unit 38P connector No. 26 (RED)
    Test point 2 Keyless access control unit connector C (24P) No. 5 (RED)
    GHH62334Courtesy of HONDA, U.S.A., INC.

    Is there continuity?

    YES 

    The F CAN wires are OK. Replace the keyless access control unit .

    NO 

    An open or poor connection in the F-CAN wires between the VSA modulator-control unit and the keyless access control unit.

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