Spectra GSX L4-1.8L (2000)
Fuel Tank Pressure Sensor: Testing and Inspection
1. Remove rear seat cushion.
2. Disconnect fuel delivery module connector and tank pressure sensor.
3. Remove three (3) fuel pump access cover screws and remove fuel pump access cover.
4. Reconnect tank pressure sensor connector.
5. Vent fuel tank by removing fuel filler cap.
6. Turn ignition switch to ON position.
7. Using voltmeter, measure voltage at all three (3) fuel tank pressure sensor terminals in the fuel tank sending unit connector.
WHT/BLK : 2.0 - 3.O V
(Signal return voltage/base reading)
8. If signal voltage reads 5.0 volts, check the sensor ground wire.
GRN/YEL : O.O V (sensor Ground)
YEL/GRN : 5.O V (Reference Voltage)
9. Disconnect hose from fuel tank at evaporative emissions canister.
10. Connect hand-held vacuum pump to hose.
11. Connect voltmeter between fuel tank ground and the WHT/BLK wire in the fuel tank sending unit connector.
12. With ignition switch in the ON position, verify that voltage goes down when vacuum is applied to canister fuel tank hose, and that voltage goes up
when pressure is applied.
13. Disconnect fuel tank pressure sensor connector, then remove the retainer nut, and remove fuel tank pressure sensor from the tank.
14. Remove screw attaching fuel tank pressure sensor ground wire to the fuel tank sending unit mounting plate.
15. Measure fuel tank pressure sensor resistance.
GRN/YEL - WHT/BLK : 5.50 kOhm
GRN/YEL- YEL/GRN : 2.75 kOhm
YEL/GRN - WHT/BLK : 5.50 kOhm
16. If not within specification, replace the fuel tank pressure sensor.
