2004 Toyota Avalon XLSFACTORY OEM SERVICE PROCEDURE

Vapor Pressure Sensor: Inspection

  1. INSPECT POWER SOURCE VOLTAGE OF VAPOR PRESSURE SENSOR 
    1. Disconnect the vapor pressure sensor connector.
    2. Turn the ignition switch ON.
    3. Using a voltmeter, measure the voltage between connector terminals VC and E2 of the wiring harness side.

      Voltage: 4.5 - 5.5 V 

      Fig 1: Inspecting Power Source Voltage Of Vapor Pressure Sensor
      G02879020Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    4. Turn the ignition switch OFF.
    5. Reconnect the vapor pressure sensor connector.
  2. INSPECT POWER OUTPUT OF VAPOR PRESSURE SENSOR 
    1. Turn the ignition switch ON.
    2. Disconnect the fuel hose from the vapor pressure sensor.
    3. Connect a voltmeter to terminals PTNK and E2 of the ECM, and measure the output voltage under the following conditions:
      1. Apply vacuum (2.0 kPa (15 mmHg, 0.59 in. Hg)) to the vapor pressure sensor.

        Voltage: 1.3-2.1 V 

      2. Release the vacuum from the vapor pressure sensor.

        Voltage: 3.0 - 3.6 V 

      3. Apply pressure (1.5 kPa (15 gf/cm2 , 0.22 psi)) to the vapor pressure sensor.

        Voltage: 4.2 - 4.8 V 

    4. Turn the ignition switch OFF.
    5. Reconnect the fuel hose to the vapor pressure sensor.
    Fig 2: Inspecting Power Output Of Vapor Pressure Sensor
    G02879021Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
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Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • • You smell fuel, burning insulation, or see smoke.
  • • Brakes feel soft, pull hard to one side, or make grinding noises.
  • • The engine overheats, stalls repeatedly, or misfires under load.
  • • You are missing required tools, torque specs, or safe lifting equipment.
  • • You are not confident in the next step or safety outcome.

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