Fuel Tank Pressure Sensor Replacement
What is a fuel tank pressure sensor?
The fuel tank pressure sensor helps control fuel vapor emissions by alerting the car's computer if there's drop in pressure.
How does the fuel tank pressure sensor work?
The sensor constantly reads pressure in the fuel tank, and is essential in testing the evaporative emissions (EVAP) system for leaks. The vehicle's computer expects a certain range of pressure in the fuel tank at any given time. If the sensor reports pressures that are unexpected, the computer will turn on the check engine light.
What are the symptoms related to a bad fuel tank pressure sensor?
The check engine light will illuminate any time there is an EVAP problem. Also, in some models, there may be a popping sound accompanying the check engine light, as the leak detection pump continuously attempts to pressurize the fuel tank.
Can I drive with a fuel tank pressure sensor problem?
A vehicle with an EVAP system issue can be driven, but may get lower fuel mileage and run roughly. Also, a vehicle with an EVAP system issue won't pass standardized state or federal emission testing.
How often do fuel tank pressure sensors need to be replaced?
EVAP system issues happen at some point to almost every vehicle. While the fuel tank pressure sensor doesn't commonly go bad, it will tell you when you have a problem with parts that fail more often, such as the gas cap. The gas cap is the number one reason EVAP failures are recorded.
How are fuel tank pressure sensor issues diagnosed?
When the EVAP system is checked, the purge valve and vent valve must be closed, and the pressure is monitored by the fuel pressure sensor. If that pressure drops with both valves closed, that means there's a leak in the EVAP system.
The sensor is also used in testing vent valve and purge valve operation. When the valves are open, the pressure sensor reads the fuel tank pressure and will note a drop in pressure. If it doesn't drop, the purge valve or vent valve may be faulty.
How is a fuel tank pressure sensor replaced?
If the sensor itself is faulty, the technician will remove all connectors, clean the surface around the faulty part, and install a new sensor. The EVAP system will then be allowed to run self-diagnostics to test the repair. If leaks are present or other components have failed, the test will fail.
RepairPal recommendations for fuel tank pressure sensor issues
To help prevent issues with the EVAP system, especially the charcoal canister, avoid overfilling or topping off the fuel tank.
When working with fuel, you should disconnect the battery and take proper precautions against fire hazards.
Can I replace the fuel tank pressure sensor myself?
Due to the risk of fire and the potential difficulty of diagnosis, EVAP system issues should be handled by a professional technician.
