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DTC P0118

DTC P0118  : ECT Sensor 1 Circuit High 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
P0118 ECT Sensor 1 Circuit High Voltage      

DTC (PGM-FI)

  1. Problem verification

    -1. Turn the vehicle to the ON mode.

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

    Signal Threshold Current conditions
    Values Unit Values Unit
    ECT SENSOR 1 More than 4.92 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 ECT sensor 1 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. ECT sensor 1 check

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

    - 2. Disconnect the following connector.

    ECT sensor 1 2P connector - Refer to: ECT Sensor 1 Removal and Installation, or ECT Sensor 2 Removal and Installation

    - 3. Connect terminals A and B with a jumper wire.

    Terminal A ECT sensor 1 2P connector No. 1 (GRY)
    Terminal B ECT sensor 1 2P connector No. 2 (PNK)
    GHH318673Courtesy of HONDA, U.S.A., INC.

    - 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
    ECT SENSOR 1 More than 4.92 V    

    Do the current condition(s) match the threshold?

    YES 

    Go to step 3.

    NO 

    Replace ECT sensor 1 - Refer to: ECT Sensor 1 Removal and Installation, or ECT Sensor 2 Removal and Installation .

  3. Determine possible failure area (TW line, SG2 line)

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

    - 2. Remove the jumper wire.

    - 3. Turn the vehicle to the ON mode.

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

    Test condition Vehicle ON mode
      ECT sensor 1 2P connector: disconnected
    Test circuit TW
    Test point 1 ECT sensor 1 2P connector No. 2 (PNK)
    Test point 2 Body ground
    GHH318674Courtesy of HONDA, U.S.A., INC.

    Is there about 5.0 V?

    YES 

    Go to step 4.

    NO 

    Go to step 5.

  4. Open wire check (SG2 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 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),  or How to Troubleshoot the Fuel and Emissions Systems,  or How to Troubleshoot the A/T System (2014 2015) 

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

    Test condition Vehicle OFF (LOCK) mode
      ECT sensor 1 2P connector: disconnected
      PCM connector B (51P): disconnected
    Test circuit SG2
    Test point 1 ECT sensor 1 2P connector No. 1 (GRY)
    Test point 2 PCM connector B (51P) No. 45 (GRY)
    GHH318675Courtesy of HONDA, U.S.A., INC.

    Is there continuity?

    YES 

    The SG2 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 (2016), or PCM Removal and Installation (2014 2015) .

    NO 

    Repair an open in the SG2 wire between the PCM (B45) and ECT sensor 1.

  5. Open wire check (TW 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 C (51P) - 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) 

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

    Test condition Vehicle OFF (LOCK) mode
      ECT sensor 1 2P connector: disconnected
      PCM connector C (51P): disconnected
    Test circuit TW
    Test point 1 ECT sensor 1 2P connector No. 2 (PNK)
    Test point 2 PCM connector C (51P) No. 48 (PNK)
    GHH318676Courtesy of HONDA, U.S.A., INC.

    Is there continuity?

    YES 

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

    NO 

    Repair an open in the TW wire between the PCM (C48) and ECT sensor 1.