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Home >> Honda >> 2021 >> Clarity Plug-In Hybrid >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System - DTC Diagnostics (P0010 - P0201) (Plug-In) >> DTC Troubleshooting >> DTC P0123
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DTC P0123

DTC P0123  : TP Sensor A Circuit High Voltage

NOTE: Before you troubleshoot, review the general troubleshooting information .
DTC Description Confirmed DTC Pending DTC
P0123 TP Sensor A Circuit High Voltage    

DTC (PGM-FI)

  1. Problem verification

    -1. Turn the vehicle to the ON mode.

    -2. Clear the DTC with the HDS.

    -3. Turn the vehicle to the OFF (LOCK) mode.

    -4. Turn the vehicle to the ON mode.

    -5. Check the parameter(s) below with the HDS.

    Signal Threshold Current conditions
    Values Unit Values Unit
    TP Sensor A More than 4.8 V    

    Data List

    Do the current condition(s) match the threshold?

    YES 

    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 on-board snapshot of this DTC is recorded, try to reproduce the failure under the same conditions with the on-board snapshot .

  2. Determine possible failure area (SG3 line, others)

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

    DTC Description Confirmed DTC Pending DTC
    P0123 TP Sensor A Circuit High Voltage    
    P0223 TP Sensor B Circuit High Voltage    

    DTC (PGM-FI)

    Are DTC P0123 and P0223 indicated at the same time?

    YES 

    Go to step 5.

    NO 

    Go to step 3.

  3. Determine possible failure area (throttle body, others)

    -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 point 1 Throttle body 6P connector (female terminals) No. 6:
    Test point 2 Body ground
    GHH417134Courtesy of HONDA, U.S.A., INC.

    Is there about 5.0 V?

    YES 

    Replace the throttle body .

    NO 

    Go to step 4.

  4. Open wire check (THL1 line)

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

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

    -3. Disconnect the following connector.

    PCM connector E (80P)

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

    Test condition Vehicle OFF (LOCK) mode
      Throttle body 6P connector: disconnected
      PCM connector E (80P): disconnected
    Test point 1 Throttle body 6P connector (female terminals) No. 6:
    Test point 2 PCM connector E (80P) No. 50
    GHH417136Courtesy of HONDA, U.S.A., INC.

    Is there continuity?

    YES 

    The THL1 wire is OK. Check for any authorized service information related to the DTCs or symptoms you are troubleshooting, or substitute a known-good PCM , then recheck. If DTC P0123 goes away and the PCM was substituted, replace the original PCM .

    NO 

    Repair an open in the THL1 wire between the PCM (E50) and the throttle body.

  5. Open wire check (SG3 line)

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

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

    -3. Disconnect the following connectors.

    PCM connector E (80P)
    Throttle body 6P connector

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

    Test condition Vehicle OFF (LOCK) mode
      PCM connector E (80P): disconnected
      Throttle body 6P connector: disconnected
    Test point 1 Throttle body 6P connector (female terminals) No. 3:
    Test point 2 PCM connector E (80P) No. 76
    GHH417138Courtesy of HONDA, U.S.A., INC.

    Is there continuity?

    YES 

    The SG3 wire is OK. Check for any authorized service information related to the DTCs or symptoms you are troubleshooting, or substitute a known-good PCM , then recheck. If DTC P0123 goes away and the PCM was substituted, replace the original PCM .

    NO 

    Repair an open in the SG3 wire between the PCM (E76) and the throttle body.