Fuel Pressure-Up System (Turbo) Test
- Ensure coolant temperature sensor and air temperature sensor (in airflow meter) and circuits are operating correctly. See applicable SENSORS or SWITCHES testing in this article.
- Fuel pressure-up system is controlled by ECU through a vacuum switching valve. The vacuum switching valve is fed current through the EFI main relay when the ignition is turned on. ECU controls the ground circuit. ECU will activate vacuum switching valve for 90-180 seconds when restarting engine at normal operating temperature.
- Remove vacuum switching valve from vehicle. The fuel pressure-up vacuum switching valve is located on the lower side of the intake manifold runners. Check for continuity across valve wiring terminals. Resistance should be about 33-50 ohms at room temperature. There should be no continuity between each terminal and body of valve. To check operation see Fig 1.
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002