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DTC Troubleshooting: U0100, U0122(Keyless Access Power Control Unit)

DTC U0100  : Power control unit (body control module) lost communication with PCM

DTC U0122  : Power control unit (body control module) lost communication with VSA/ABS modulator-control unit

NOTE: 

DTC Description DTC
U0100 Power control unit (body control module) lost communication with PCM  
U0122 Power control unit (body control module) lost communication with VSA/ABS modulator-control unit  

DTC (Power Control Unit)

  1. CAN gateway system DTC check

    -1. 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  
    U0056-00 CAN Gateway F-CAN ch C Bus Off  
    U0065-00 CAN Gateway F-CAN ch D Bus Off  
    U3000-49 CAN Gateway Internal Failure  

    DTC (CAN GATEWAY)

    Is DTC U0029-00, U0047-00, U0056-00, U0065-00, 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

    Does the acoustic vehicle alerting control unit detect the CAN gateway Bus channels B?

    Bus B is Not Available

    Go to step 3.

    Bus B is Available

    Go to step 4.

  3. Open wire check (F-CAN B lines)

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

    -2. Disconnect the following connectors.

    CAN gateway 16P connector
    Body control module connector B (36P)

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

    Test condition Vehicle OFF (LOCK) mode

    CAN gateway 16P connector: disconnected

    Gauge control module connector A (32P): disconnected
    Test point 1 CAN gateway 16P connector (female terminals) No. 6:
    Test point 2 Body control module connector B (36P) No. 22
    Test point 1 CAN gateway 16P connector (female terminals) No. 14:
    Test point 2 Body control module connector B (36P) No. 23
    GHH419562Courtesy of HONDA, U.S.A., INC.

    Is there continuity?

    YES 

    The F-CAN B_H and F-CAN B_L wires are OK. Replace the body control module .

    NO 

    Repair an open in F-CAN B_H or F-CAN B_L wire.

  4. F-CAN circuit communication check (Transmitting control unit)

    -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

    According to the detected DTC on the following table, make sure that the transmitting control unit detects the CAN gateway Bus channel(s) normally.

    DTC Transmitting control unit Detected CAN gateway Bus channel(s) at normal
    U0100 PCM A, B
    U0122 VSA modulator-control unit B, C

    Is it detected normally?

    Detected normal

    Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the transmitting control unit and the CAN gateway.

    U0100: PCM is Not Available for Bus A

    Go to step 5.

    U0100: PCM is Not Available for Bus B

    Go to step 6.

    U0122: VSA modulator-control unit is Not Available for Bus B

    Go to step 6.

    U0122: VSA modulator-control unit is Not Available for Bus C

    Go to step 7.

  5. Open wire check (F-CAN A lines)

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

    -2. U0100: Jump the SCS line with the HDS and wait more than 1 minute.

    SCS short

    -3. According to the detected DTC on the following table, disconnect the transmitting control unit connector(s).

    DTC Connector
    - CAN gateway 16P connector
    U0100 PCM connector A (50P)

    -4. Check for continuity between test points 1 and 2.

    Test condition Vehicle OFF (LOCK) mode
      CAN gateway 16P connector: disconnected
      PCM connector A (50P): disconnected
    DTC Circuit name Test point 1 (Receiving control unit) Test point 2 (Transmitting control unit)
    Connector Terminal Connector Terminal
    U0100 F-CAN A_H CAN gateway 16P connector (female terminals): No. 3 PCM connector A (50P) No. 37
    F-CAN A_L No. 11 No. 36
    GHH419564Courtesy of HONDA, U.S.A., INC.

    Is there continuity?

    YES 

    The F-CAN A_H wire and the F-CAN A_L wire are OK.Refer to the DTC shown on the display, then substitute or replace the control unit based on the instructions (see table).

    DTC Operation for transmitting control unit
    U0100 PCM

    NO 

    Repair an open in F-CAN A_H or F-CAN A_L wire.

  6. Open wire check (F-CAN B lines)

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

    -2. U0100: Jump the SCS line with the HDS and wait more than 1 minute.

    SCS short

    -3. According to the detected DTC on the following table, disconnect the transmitting control unit connector(s).

    DTC Connector
    - CAN gateway 16P connector
    U0100 PCM connector A (50P)
    U0122 VSA modulator-control unit 46P connector

    -4. Check for continuity between test points 1 and 2.

    Test condition Vehicle OFF (LOCK) mode
      CAN gateway 16P connector: disconnected
      Transmitting control unit connector(s) for indicated DTCs: disconnected
    DTC Circuit name Test point 1 (Receiving control unit) Test point 2 (Transmitting control unit)
    Connector Terminal Connector Terminal
    U0100 F-CAN B_H CAN gateway 16P connector (female terminals): No. 6 PCM connector A (50P) No. 39
    F-CAN B_L No. 14 No. 38
    U0122 F-CAN B_H CAN gateway 16P connector (female terminals): No. 6 VSA modulator-control unit 46P connector No. 46
    F-CAN B_L No. 14 No. 34
    GHH419567Courtesy of HONDA, U.S.A., INC.

    Is there continuity?

    YES 

    The F-CAN B_H wire and the F-CAN B_L wire are OK.Refer to the DTC shown on the display, then substitute or replace the control unit based on the instructions (see table).

    DTC Operation for transmitting control unit
    U0100 PCM
    U0122 VSA modulator-control unit

    NO 

    Repair an open in F-CAN B_H or F-CAN B_L wire.

  7. Open wire check (F-CAN C lines)

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

    -2. According to the detected DTC on the following table, disconnect the transmitting control unit connector(s).

    DTC Connector
    - CAN gateway 16P connector
    U0122 VSA modulator-control unit 46P connector

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

    Test condition Vehicle OFF (LOCK) mode
      CAN gateway 16P connector: disconnected
      VSA modulator-control unit 46P connector: disconnected
    DTC Circuit name Test point 1 (Receiving control unit) Test point 2 (Transmitting control unit)
    Connector Terminal Connector Terminal
    U0122 F-CAN C_H CAN gateway 16P connector (female terminals): No. 5 VSA modulator-control unit 46P connector No. 40
    F-CAN C_L No. 13 No. 28
    GHH419569Courtesy of HONDA, U.S.A., INC.

    Is there continuity?

    YES 

    The F-CAN C_H wire and the F-CAN C_L wire are OK.Refer to the DTC shown on the display, then substitute or replace the control unit based on the instructions (see table).

    DTC Operation for transmitting control unit
    U0122 VSA modulator-control unit

    NO 

    Repair an open in F-CAN C_H or F-CAN C_L wire.

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