FixVault

DTC P0122

DTC P0122  : TP Sensor A Circuit Low Voltage

NOTE: Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information .
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.

  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)
    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
    GHH344418Courtesy 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, then do the repair verification.

    NO 

    The THL1 wire is OK. Update the PCM if it does not have the latest software, or substitute a known-good PCM , then do the repair verification.

  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
    GHH344419Courtesy of HONDA, U.S.A., INC.

    Is there about 5.0 V?

    YES 

    Replace the throttle body , then do the repair verification.

    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)

    -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)
    GHH344420Courtesy 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 , then do the repair verification.

    NO 

    Repair an open in the VCC5 wire between the PCM (B44) and the throttle body, then do the repair verification.

  6. Repair verification

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

    -2. Reconnect all connectors.

    -3. Exit the SCS mode with the HDS.

    -4. Turn the vehicle to the ON mode.

    -5. Reset the PCM with the HDS .

    Reset PCM

    -6. Do the PCM idle learn procedure.

    -7. Check for Pending or Confirmed DTCs with the HDS.

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

    DTC (PGM-FI)

    Is DTC P0122 indicated?

    YES 

    Check for poor connections or loose terminals at the throttle body and the PCM. If the PCM was updated, substitute a known-good PCM , then recheck. If the PCM was substituted, go to step 1.

    NO 

    Troubleshooting is complete. If the PCM was substituted, replace the original PCM . If any other Pending or Confirmed DTCs are indicated, go to the indicated DTC's troubleshooting.