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Home >> Acura >> 2014 >> MDX SH-AWD >> Repair and Diagnosis >> Engine Performance >> Testing & Diagnosis >> Engine Control System - DTC Diagnostics (5 Of 5) (Except Hybrid) >> DTC Troubleshooting >> DTC U0047 (2016 2017 2018 PGM-FI System (Without CAN Gateway))

DTC U0047 (2016 2017 2018 PGM-FI System (Without CAN Gateway))

DTC U0047  : F-CAN Malfunction For The Second Channel (BUS-OFF (PCM))

NOTE: Before you troubleshoot, review the general troubleshooting information - Refer to: How to Troubleshoot the Fuel and Emissions Systems, or How to Troubleshoot the Brake Booster Pressure Monitoring System (2016 2017 2018 2019 2020), or How to Troubleshoot the Fuel and Emissions Systems(With Auto Idle Stop System) (2016 2017 2018 2019 2020) .
DTC Description Confirmed DTC Pending DTC Freeze Frame
U0047 F-CAN Malfunction For The Second Channel (BUS-OFF (PCM))      

DTC (PGM-FI)

  1. Problem verification

    -1. Turn the vehicle to the ON mode.

    - 2. Clear the DTC with the HDS.

    - 3. Check for Pending or Confirmed DTCs with the HDS.

    DTC Description Confirmed DTC Pending DTC Freeze Frame
    U0047 F-CAN Malfunction For The Second Channel (BUS-OFF (PCM))      

    Is DTC U0047 indicated?

    YES 

    The failure is duplicated. Go to step 2.

    NO 

    Intermittent failure, the system is OK at this time. 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.

  2. F-CAN B circuit resistance check

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

    - 2. Jump the SCS line with the HDS.

    - 3. Disconnect the following connector.

    PCM connector A (51P)

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

    Test condition Vehicle OFF (LOCK) mode
      PCM connector A (51P): disconnected
    Test point 1 PCM connector A (51P) No. 11 - Refer to: PCM Connector for Inputs and Outputs (2017 2018 2019 2020), or PCM Connector for Inputs and Outputs (2016)
    Test point 2 PCM connector A (51P) No. 12 - Refer to: PCM Connector for Inputs and Outputs (2016), or PCM Connector for Inputs and Outputs (2017 2018 2019 2020)

    Is there about 52-65 -Ω

    YES 

    Go to step 10.

    NO 

    Go to step 3.

  3. Shorted wire check (F-CAN B_H line to F-CAN B_L line)

    -1. Disconnect the following connectors.

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

    Test condition Vehicle OFF (LOCK) mode
    PCM connector A (51P): disconnected
    TCM 58P connector: disconnected
    SBW shifter control module 20P connector: disconnected
    VSA modulator-control unit 38P connector: disconnected
    Test point 1 PCM connector A (51P) No. 11 - Refer to: PCM Connector for Inputs and Outputs (2017 2018 2019 2020), or PCM Connector for Inputs and Outputs (2016)
    Test point 2 PCM connector A (51P) No. 12 - Refer to: PCM Connector for Inputs and Outputs (2017 2018 2019 2020), or PCM Connector for Inputs and Outputs (2016)

    Is there continuity?

    YES 

    Repair a short in the F-CAN B_H wire to F-CAN B_L wire between PCM terminals A11 and A12.

    NO 

    The F-CAN B_H and F-CAN B_L wires are not shorted. Go to step 4.

  4. Open wire check (F-CAN B_H line) 1

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

    Test condition Vehicle OFF (LOCK) mode
    PCM connector A (51P): disconnected
    TCM 58P connector: disconnected
    SBW shifter control module 20P connector: disconnected
    VSA modulator-control unit 38P connector: disconnected
    Test point 1 TCM 58P connector No. 7
    Test point 2 PCM connector A (51P) No. 11 - Refer to: PCM Connector for Inputs and Outputs (2014 2015), or PCM Connector for Inputs and Outputs (2016), or PCM Connector for Inputs and Outputs (2017 2018 2019 2020)

    Is there continuity?

    YES 

    The F-CAN B_H wire is not open. Go to step 5.

    NO 

    Repair an open in the F-CAN B_H wire between the PCM (A11) and the TCM.

  5. Open wire check (F-CAN B_H line) 2

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

    Test condition Vehicle OFF (LOCK) mode
    PCM connector A (51P): disconnected
    TCM 58P connector: disconnected
    SBW shifter control module 20P connector: disconnected
    VSA modulator-control unit 38P connector: disconnected
    Test point 1 VSA modulator-control unit 38P connector No. 31 - Refer to: VSA Modulator-Control Unit Connector for Inputs and Outputs (2014 2015), or VSA Modulator-Control Unit Connector for Inputs and Outputs (2016), or VSA Modulator-Control Unit Connector for Inputs and Outputs (2017 2018 2019 2020)
    Test point 2 PCM connector A (51P) No. 11 - Refer to: PCM Connector for Inputs and Outputs (2014 2015), or PCM Connector for Inputs and Outputs (2016), or PCM Connector for Inputs and Outputs (2017 2018 2019 2020)

    Is there continuity?

    YES 

    The F-CAN B_H wire is not open. Go to step 6.

    NO 

    Repair an open in the F-CAN B_H wire between the PCM (A11) and the VSA modulator-control unit.

  6. Open wire check (F-CAN B_L line) 1

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

    Test condition Vehicle OFF (LOCK) mode
    PCM connector A (51P): disconnected
    TCM 58P connector: disconnected
    SBW shifter control module 20P connector: disconnected
    VSA modulator-control unit 38P connector: disconnected
    Test point 1 TCM 58P connector No. 20
    Test point 2 PCM connector A (51P) No. 12 - Refer to: PCM Connector for Inputs and Outputs (2014 2015), or PCM Connector for Inputs and Outputs (2016), or PCM Connector for Inputs and Outputs (2017 2018 2019 2020)

    Is there continuity?

    YES 

    The F-CAN B_L wire is not open. Go to step 7.

    NO 

    Repair an open in the F-CAN B_L wire between the PCM (A12) and the TCM.

  7. Open wire check (F-CAN B_L line) 2

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

    Test condition Vehicle OFF (LOCK) mode
    PCM connector A (51P): disconnected
    TCM 58P connector: disconnected
    SBW shifter control module 20P connector: disconnected
    VSA modulator-control unit 38P connector: disconnected
    Test point 1 VSA modulator-control unit 38P connector No. 20 - Refer to: VSA Modulator-Control Unit Connector for Inputs and Outputs (2014 2015), or VSA Modulator-Control Unit Connector for Inputs and Outputs (2016), or VSA Modulator-Control Unit Connector for Inputs and Outputs (2017 2018 2019 2020)
    Test point 2 PCM connector A (51P) No. 12 - Refer to: PCM Connector for Inputs and Outputs (2014 2015), or PCM Connector for Inputs and Outputs (2016), or PCM Connector for Inputs and Outputs (2017 2018 2019 2020)

    Is there continuity?

    YES 

    The F-CAN B_L wire is not open. Go to step 8.

    NO 

    Repair an open in the F-CAN B_L wire between the PCM (A12) and the VSA modulator-control unit.

  8. VSA modulator-control unit internal resistance check

    -1. Reconnect the VSA modulator-control unit 38P connector.

    - 2. Measure the resistance between test points 1 and 2.

    Test condition Vehicle OFF (LOCK) mode
    PCM connector A (51P): disconnected
    TCM 58P connector: disconnected
    SBW shifter control module 20P connector: disconnected
    Test point 1 PCM connector A (51P) No. 11 - Refer to: PCM Connector for Inputs and Outputs (2017 2018 2019 2020), or PCM Connector for Inputs and Outputs (2016)
    Test point 2 PCM connector A (51P) No. 12 - Refer to: PCM Connector for Inputs and Outputs (2016), or PCM Connector for Inputs and Outputs (2017 2018 2019 2020)

    Is there about 108-132 -Ω

    YES 

    The VSA modulator-control unit is OK. Go to step 9.

    NO 

    Replace the VSA modulator-control unit .

  9. SBW shifter control module internal resistance check

    -1. Disconnect the following connector.

    VSA modulator-control unit 38P connector

    - 2. Reconnect the SBW shifter control module 20P connector.

    - 3. Measure the resistance between test points 1 and 2.

    Test condition Vehicle OFF (LOCK) mode
    PCM connector A (51P): disconnected
    TCM 58P connector: disconnected
    VSA modulator-control unit 38P connector: disconnected
    Test point 1 PCM connector A (51P) No. 11 - Refer to: PCM Connector for Inputs and Outputs (2017 2018 2019 2020), or PCM Connector for Inputs and Outputs (2016)
    Test point 2 PCM connector A (51P) No. 12 - Refer to: PCM Connector for Inputs and Outputs (2017 2018 2019 2020), or PCM Connector for Inputs and Outputs (2016)

    Is there about 108-132 -Ω

    YES 

    The SBW shifter control module is OK. Update the PCM if it does not have the latest software, or substitute a known-good PCM - Refer to: PCM Removal and Installation (2016) .

    NO 

    Replace the SBW shifter control module .

  10. Shorted wire check (F-CAN B_H line)

    -1. Disconnect the following connectors.

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

    Test condition Vehicle OFF (LOCK) mode
    PCM connector A (51P): disconnected
    TCM 58P connector: disconnected
    SBW shifter control module 20P connector: disconnected
    VSA modulator-control unit 38P connector: disconnected
    Test point 1 PCM connector A (51P) No. 11 - Refer to: PCM Connector for Inputs and Outputs (2016), or PCM Connector for Inputs and Outputs (2017 2018 2019 2020)
    Test point 2 Body ground

    Is there continuity?

    YES 

    Repair a short in the F-CAN B_H wire between the PCM (A11) and the TCM, the SBW shifter control module, or the VSA modulator-control unit.

    NO 

    The F-CAN B_H wire is OK. Go to step 11.

  11. Shorted wire check (F-CAN B_L line)

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

    Test condition Vehicle OFF (LOCK) mode
    PCM connector A (51P): disconnected
    TCM 58P connector: disconnected
    SBW shifter control module 20P connector: disconnected
    VSA modulator-control unit 38P connector: disconnected
    Test point 1 PCM connector A (51P) No. 12 - Refer to: PCM Connector for Inputs and Outputs (2016), or PCM Connector for Inputs and Outputs (2017 2018 2019 2020)
    Test point 2 Body ground

    Is there continuity?

    YES 

    Repair a short in the F-CAN B_L wire between the PCM (A12) and the TCM, the SBW shifter control module, or the VSA modulator-control unit.

    NO 

    The F-CAN A_L wire is OK. Go to step 12.

  12. Shorted unit check (TCM)

    -1. Reconnect the following connector.

    PCM connector A (51P) - Refer to: PCM Removal and Installation (2016 2017 2018 2019 2020)
    SBW shifter control module 20P connector
    VSA modulator-control unit 38P connector

    - 2. Turn the vehicle to the ON mode.

    - 3. Clear the DTC with the HDS.

    - 4. Check for Pending or Confirmed DTCs with the HDS.

    DTC Description Confirmed DTC Pending DTC Freeze Frame
    U0047 F-CAN Malfunction For The Second Channel (BUS-OFF (PCM))      

    Is DTC U0047 indicated?

    YES 

    Go to step 13.

    NO 

    Update the TCM if it does not have the latest software, or substitute a known-good TCM , then recheck. If DTC U0047 goes away and the TCM was updated, troubleshooting is complete. If DTC U0047 goes away and the TCM was substituted, replace the original TCM .

  13. Shorted unit check (SBW shifter control module)

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

    - 2. Reconnect the TCM 58P connector.

    - 3. Disconnect the following connector.

    SBW shifter control module 20P connector

    - 4. Turn the vehicle to the ON mode.

    - 5. Clear the DTC with the HDS.

    - 6. Check for Pending or Confirmed DTCs with the HDS.

    DTC Description Confirmed DTC Pending DTC Freeze Frame
    U0047 F-CAN Malfunction For The Second Channel (BUS-OFF (PCM))      

    Is DTC U0047 indicated?

    YES 

    Go to step 14.

    NO 

    Substitute a known-good SBW shifter control module , then recheck. If DTC U0047 goes away and the SBW shifter control module was substituted, replace the original SBW shifter control module .

  14. Shorted unit check (VSA modulator-control unit)

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

    - 2. Reconnect the SBW shifter control module 20P connector.

    - 3. Disconnect the following connector.

    VSA modulator-control unit 38P connector

    - 4. Turn the vehicle to the ON mode.

    - 5. Clear the DTC with the HDS.

    - 6. Check for Pending or Confirmed DTCs with the HDS.

    DTC Description Confirmed DTC Pending DTC Freeze Frame
    U0047 F-CAN Malfunction For The Second Channel (BUS-OFF (PCM))      

    Is DTC U0047 indicated?

    YES 

    Update the PCM if it does not have the latest software, or substitute a known-good PCM - Refer to: PCM Removal and Installation (2016 2017 2018 2019 2020) .

    NO 

    Update the VSA modulator-control unit if it does not have the latest software, then recheck. If DTC U0047 goes away and the VSA modulator-control unit was updated, troubleshooting is complete. If DTC U0047 is indicated after the VSA modulator-control unit was updated, replace the VSA modulator-control unit .

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