Fuel Tank Pressure Sensor: Testing and Inspection

FUEL TANK PRESSURE SENSOR (FTPS)

INSPECTION




FUNCTION AND OPERATION PRINCIPLE
The evaporative emission control system prevents hydro-carbon vapors from escaping from the fuel tank into the atmosphere where they could form photochemical smog. Gasoline vapors are collected in the charcoal canister. The Fuel Tank Pressure Sensor (FTPS) is installed on fuel pump assembly and is an integral part of the evaporative monitoring system. The ECM monitors the FTPS signal to detect vacuum decay and excess vacuum. The FTPS measures the difference between the air pressure inside the fuel tank and atmospheric air pressure to check the purge control solenoid valve operation and for leak detection in the evaporative emission control system by monitoring pressure and vacuum levels in the fuel tank during the purge control solenoid valve operating cycles.

SPECIFICATION
Pressure (kPa) Output Voltage (V)
-3.75 4.5
0 1.5
+1.25 0.5

Condition Output (V)
Idle Approx. 1.5 V

Schematic Diagram:

SCHEMATIC DIAGRAM

COMPONENT INSPECTION
1. Connect a scantool on Diagnosis connector (DLC).
2. Check FTPS output voltage at idle.