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Home >> Lexus >> 2008 >> RX 400h AWD >> Repair and Diagnosis >> Engine Performance >> Engine Control System >> SFI System >> DTC P1451 Fuel Tank Pressure Sensor Range/Performance; DTC P1452 Fuel Tank Pressure Sensor Low Input; DTC P1453 Fuel Tank Pressure Sensor High Input >> Inspection Procedure

Inspection Procedure

NOTE:
  • When a vehicle is brought into the workshop, leave it as it is. Do not change the vehicle condition. For example, do not tighten the fuel tank cap.
  • Do not disassemble the pump module.
  • The Techstream is required to conduct the following diagnostic troubleshooting procedure.
  1. CONFIRM DTC AND FUEL TANK PRESSURE 
    1. Connect Techstream to the DLC3.
    2. Turn the ignition switch to the ON position.
    3. Turn the tester on.
    4. Enter the following menus: Powertrain / Engine and ECT / Trouble Code.
    5. Read the DTCs.
    6. Enter the following menus: Powertrain / Engine and ECT / Data List / Vapor Pressure Tank.
    7. Read the EVAP (Evaporative Emission) pressure displayed on the tester.

      Result 

      RESULT CHART

      Display (DTC Output) Test Result Suspected Trouble Area Proceed to
      P1451 -
      • Pressure sensor
      C
      P1450 and/or P1452 Less than -17.187 kPa (-128.93 mmHg)
      • Wire harness/connector (HV control ECU - pressure sensor)
      • Pressure sensor
      • Short in ECM (included in HV control ECU) circuit
      A
      P1450 and/or P1453 More than 23.5 kPa (176.69 mmHg)
      • Wire harness/connector (HV control ECU - pressure sensor)
      • Pressure sensor
      • Open in ECM (included in HV control ECU) circuit
      B

    B: Go to step  4

    C:  GO TO EVAP System  for EVAP INSPECTION PROCEDURE

    A: Go to Next Step 

  2. CHECK HARNESS AND CONNECTOR (FUEL TANK PRESSURE SENSOR - HV CONTROL ECU) 
    1. Turn the ignition switch off.
    2. Disconnect the H30 HV control ECU connector.
    3. Measure the resistance between the PTNK terminal of the HV control ECU connector and body ground.
      Fig 1: Identifying Terminals Of H30 HV Control ECU Connector
      G05275659Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      Result 

      RESULT CHART

      Test Result Suspected Trouble Area Proceed to
      10 Ω or less
      • Wire harness/connector (HV control ECU - pressure sensor)
      • Short in pressure sensor circuit
      A
      10 kΩ or more
      • Wire harness/connector (HV control ECU - pressure sensor)
      • Short in ECM (included in HV control ECU) circuit
      B
    4. Reconnect the HV control ECU connector.

    B: Go to step  7

    A: Go to Next Step 

  3. CHECK HARNESS AND CONNECTOR (FUEL TANK PRESSURE SENSOR - HV CONTROL ECU) 
    1. Remove the fuel tank assembly.
    2. Disconnect the V11 fuel tank pressure sensor connector.
    3. Disconnect the H30 HV control ECU connector.
    4. Measure the resistance between the PTNK terminal of the HV control ECU connector and body ground.
      Fig 2: Identifying Terminals Of H30 HV Control ECU Connector
      G05275660Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      Result 

      RESULT CHART

      Test Result Suspected Trouble Area Proceed to
      10 kΩ or more
      • Short in pressure sensor circuit
      A
      10 Ω or less
      • Short in wire harness/connector (HV control ECU - pressure sensor)
      B
    5. Reconnect the pressure sensor connector.
    6. Reconnect the HV control ECU connector.

    A: Go to step  5

    B: Go to step  6

  4. CHECK HARNESS AND CONNECTOR (FUEL TANK PRESSURE SENSOR - HV CONTROL ECU) 
    1. Remove the fuel tank assembly.
    2. Disconnect the V11 fuel tank pressure sensor connector.
    3. Turn the ignition switch to the ON position.
    4. Measure the voltage and resistance according to the value (s) in the table below.

      Standard 

      TESTER CONNECTION SPECIFIED CONDITION CHART

      Tester Connection Specified Condition
      V11-3 - Body ground 4.5 to 5.0 V
      V11-2 - Body ground 100 Ω or less
      Fig 3: Identifying Terminals Of V11 Fuel Tank Pressure Sensor Connector
      G05200121Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      Result 

      RESULT CHART

      Test Result Suspected Trouble Area Proceed to
      Voltage and resistance within standard ranges
      • Open in pressure sensor circuit
      A
      Voltage and resistance outside standard ranges
      • Open in wire harness/connector (HV control ECU - pressure sensor)
      B
    5. Reconnect the canister connector.

    B: Go to step  6

    A: Go to Next Step 

  5. REPLACE FUEL TANK PRESSURE SENSOR 

    NEXT: Go to step  8

  6. REPAIR OR REPLACE HARNESS OR CONNECTOR 

    HINT:

    If the exhaust tail pipe has been removed, go to the next step before reinstalling it.

    NEXT: Go to step  8

  7. REPLACE HV CONTROL ECU 

    NEXT: Go to step 8 

  8. CHECK WHETHER DTC OUTPUT RECURS (AFTER REPAIR) 
    1. Connect Techstream to the DLC3.
    2. Turn the ignition switch to the ON position and turn the tester on.
    3. Wait for at least 60 seconds.
    4. Enter the following menus: Powertrain / Engine and EOT / Trouble Codes / Pending.

      HINT:

      If no pending DTC is displayed on the tester, the repair has been successfully completed.

    NEXT: COMPLETED