Fuel Tank Pressure Sensor: Testing and Inspection

Fuel Tank Vapor Pressure Sensor Diagnosis (1 Of 2):

Fuel Tank Vapor Pressure Sensor Diagnosis (2 Of 2):

Circuit Description
The fuel tank vapor pressure sensor is used to detect vacuum decay and excessive vacuum during the EVAP diagnostic routine. The sensor responds to changes in fuel tank pressure or vacuum. The signal voltage to the Control Module varies from a minimum of about 0.2 volts with pressure in the fuel tank to above 4 volts with a high vacuum in the fuel tank
The Fuel Tank Vacuum display on the scan tool has an auto zero feature which occurs at each ignition cycle and is corrected according to barometric pressure. Because of this, Fuel Tank Vacuum may not accurately reflect the actual output of the sensor or conditions within the fuel tank.
The Fuel Tank Vapor Pressure Sensor Diagnosis Table is intended to isolate and diagnose electrical problems with the sensor wiring or the sensor.