Leak Detection Sensor: Testing and Inspection

Fuel Tank Pressure Sensor Check
1) Remove fuel tank pressure sensor from fuel tank
2) Check sensor air vent hole and pressure passage for clog. Clean if clogged.
3) Arrange 3 new 1.5V batteries in series (check that total voltage is 4.5-5.OV) and connect its positive terminal to "Vin" terminal of sensor and negative terminal to "Ground" terminal. Then check voltage between "Vout" and "Ground."
Also, check it voltage reduces when vacuum is applied up to 6.6kPa (50mmHg) by using vacuum pump and if it increases when positive pressure applied up to 6.6kPa (50mmHg) by using hand pump.
If measured voltage doesn't show such characteristic as shown in left figure, replace.