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DTC P0122

DTC P0122  : TP Sensor A Circuit Low Voltage

NOTE:  Before you troubleshoot, review the general troubleshooting information - Refer to: How to Troubleshoot the A/T System (2014 2015),  or 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) .

DTC Description Confirmed DTC Pending DTC Freeze Frame
P0122 TP Sensor A Circuit Low Voltage      

DTC (PGM-FI)

  1. Problem verification

    -1. Turn the vehicle to the ON mode.

    - 2. Clear the DTC with the HDS.

    - 3. Check the parameter(s) below with the HDS.

    Signal Threshold Current conditions
    Values Unit Values Unit
    TP SENSOR A Less than 0.3 V    

    Do the current condition(s) match the threshold?

    YES 

    The failure is duplicated. Go to step 2.

    NO 

    Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the throttle body and the PCM. 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. Determine possible failure area (VCC5 line, THL1 line)

    -1. Check for Pending or Confirmed DTCs with the HDS.

    DTC Description Confirmed DTC Pending DTC Freeze Frame
    P0122 TP Sensor A Circuit Low Voltage      
    P0222 TP Sensor B Circuit Low Voltage      

    Are DTC P0122 and P0222 indicated at the same time?

    YES 

    Go to step 4.

    NO 

    Go to step 3.

  3. Shorted wire check (THL1 line)

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

    - 2. Jump the SCS line with the HDS.

    - 3. Disconnect the following connectors.

    PCM connector B (51P) - Refer to: How to Troubleshoot the Fuel and Emissions Systems,  or How to Troubleshoot the A/T System (2014 2015),  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) 
    Throttle body 6P connector

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

    Test condition Vehicle OFF (LOCK) mode
      PCM connector B (51P): disconnected
      Throttle body 6P connector: disconnected
    Test circuit THL1
    Test point 1 Throttle body 6P connector No. 6 (RED)
    Test point 2 Body ground
    GHH318689Courtesy of HONDA, U.S.A., INC.

    Is there continuity?

    YES 

    Repair a short in the THL1 wire between the PCM (B31) and the throttle body.

    NO 

    The THL1 wire 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 (2014 2015), or PCM Removal and Installation (2016) .

  4. Determine possible failure area (VCC5 line, throttle body)

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

    - 2. Disconnect the following connector.

    Throttle body 6P connector

    - 3. Turn the vehicle to the ON mode.

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

    Test condition Vehicle ON mode
      Throttle body 6P connector: disconnected
    Test circuit VCC5
    Test point 1 Throttle body 6P connector No. 5 (BLU)
    Test point 2 Body ground
    GHH318690Courtesy of HONDA, U.S.A., INC.

    Is there about 5.0 V?

    YES 

    Replace the throttle body .

    NO 

    Go to step 5.

  5. Open wire check (VCC5 line)

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

    - 2. Jump the SCS line with the HDS.

    - 3. Disconnect the following connector.

    PCM connector B (51P) - Refer to: How to Troubleshoot the Fuel and Emissions Systems,  or How to Troubleshoot the A/T System (2014 2015),  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) 

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

    Test condition Vehicle OFF (LOCK) mode
      Throttle body 6P connector: disconnected
      PCM connector B (51P): disconnected
    Test circuit VCC5
    Test point 1 Throttle body 6P connector No. 5 (BLU)
    Test point 2 PCM connector B (51P) No. 44 (BLU)
    GHH318691Courtesy of HONDA, U.S.A., INC.

    Is there continuity?

    YES 

    The VCC5 wire 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 (2014 2015), or PCM Removal and Installation (2016) .

    NO 

    Repair an open in the VCC5 wire between the PCM (B44) and the throttle body.