FixVault

Vapor Pressure Sensor

  1. Ensure ignition is off. To test vapor pressure sensor supply voltage, disconnect electrical connector from vapor pressure sensor. See Figure. See VAPOR PRESSURE SENSOR LOCATION  table.
    VAPOR PRESSURE SENSOR LOCATION

    Application Location
    Avalon On Firewall, Near Passenger's Side Of Brake Booster & Contains Black 3-Pin Electrical Connector
  2. Turn ignition on. Using voltmeter, measure voltage between terminals VC and E2 on wiring harness side of electrical connector for vapor pressure sensor. The VC and E2 terminals are the 2 outer terminals. DO NOT use center terminal. Supply voltage should be 4.5-5.5 volts.
  3. If supply voltage is not within specification, check wiring circuit. See appropriate wiring diagram in WIRING DIAGRAMS article. If supply voltage is within specification, turn ignition off. Reinstall electrical connector on vapor pressure sensor.
  4. To test vapor pressure sensor output voltage, turn ignition on. Disconnect vacuum hose from vapor pressure sensor. Connect voltmeter between specified terminals on Engine Control Module (ECM). ECM is located behind glove box. See Fig 1. See ECM TERMINAL APPLICATION  table.
    ECM TERMINAL APPLICATION

    Application & Terminal No. Wire Color
    13 Pink
    22 Brown
  5. Using vacuum pump, apply .59 in. Hg of vacuum to vapor pressure sensor. Ensure output voltage is within specification. See VAPOR SENSOR OUTPUT VOLTAGE  table.
  6. Release vacuum from vapor pressure sensor. Ensure output voltage is within specification. See VAPOR SENSOR OUTPUT VOLTAGE  table.
  7. Apply .22 psi (.015 kg/cm2 ) to vapor pressure sensor. Ensure output voltage is within specification. See VAPOR SENSOR OUTPUT VOLTAGE  table. Replace vapor sensor if output voltage is not within specification. Reconnect vacuum hose.
VAPOR SENSOR OUTPUT VOLTAGE

Condition Output Voltage
Vacuum Applied 1.3-2.1
Vacuum Released 2.9-3.7
Pressure Applied 4.2-4.8
Fig 1: Measuring Vapor Pressure Sensor Output Voltage
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