Vapor Pressure Sensor (Sequoia, Sienna & 4Runner)
WARNING: This page does not describe the selected car, but rather 10 other vehicles, including the 2002 Toyota Tundra, 2002 Toyota Tacoma, 2002 Toyota Sienna, 2002 Toyota Sequoia, and 2002 Toyota Land Cruiser. However, it is still accessible from the selected car via links, so may be relevant.
- Ensure ignition is off. To test vapor pressure sensor supply voltage, obtain access to electrical connector at vapor pressure sensor. Vapor pressure sensor is located on top of fuel pump assembly on top of fuel tank and uses a Black 3-pin electrical connector. See Figure, Figure and Figure . On Sequoia and Sienna, it may be necessary to lower fuel tank for access to vapor pressure sensor. On 4Runner, vapor pressure sensor may be accessed by removing remove driver's side rear seat cushion and cover plate on floor panel.
- On all models, disconnect electrical connector from vapor pressure sensor. Turn ignition on. Using voltmeter, measure vapor pressure sensor supply voltage between terminals No. 1 and 3 on wiring harness side of electrical connector for vapor pressure sensor. See Fig 1. DO NOT use center terminal. Vapor pressure sensor supply voltage should be 4.5-5.5 volts.
- If vapor pressure sensor supply voltage is within specification, turn ignition off. Reinstall electrical connector on vapor pressure sensor. Go to next step. If vapor pressure sensor supply voltage is not within specification, check wiring circuit between Engine Control Module (ECM) and vapor pressure sensor. See WIRING DIAGRAMS article. On Sequoia, ECM is located behind glove box and heater duct. On Sienna, ECM is located at passenger's side of instrument panel, just below glove box. On 4Runner, ECM is located behind glove box. On all models, for illustration of ECM location, see THEORY & OPERATION article.
- To test vapor pressure sensor output voltage, turn ignition on. Remove fuel tank cap. Using voltmeter, measure vapor pressure sensor output voltage between terminals No. 2 and 3 on wiring harness side of electrical connector for vapor pressure sensor with electrical connector installed on vapor pressure sensor. See Fig 1.
- Vapor pressure sensor output voltage should be 3.0-3.6 volts. Replace vapor sensor if vapor pressure sensor output voltage is not within specification. See VAPOR PRESSURE SENSOR under EMISSION SYSTEMS & SUB-SYSTEMS in REMOVAL, OVERHAUL & INSTALLATION - V6 & V8 article. Turn ignition off. Reinstall fuel tank cap.