Functional Description - Fuel Tank Isolation Valve (FTIV)
WARNING: This page is about a different variant/trim than selected.
The normally closed Fuel Tank Isolation (FTIV), located between the Fuel Tank and Charcoal Canister, is used to manage pressure and vacuum in the Fuel Tank. When the FTIV is closed it splits the Evaporative system into two separate sections that can be diagnosed during leak testing, the "fresh air side" and "fuel tank side".
- During normal engine operation the FTIV is mechanically opened to relieve excess Fuel Tank pressure above approximately 35kPa (4.64psi) and excess vacuum below approximately -14.0kPa (-2.03psi).
- During a refueling event when the fuel door release is pressed, the Fuel Tank Pressure (FTP) Sensor input is monitored and the FTIV is energized (opened) by the PCM to relieve the tank pressure at a controlled rate. When the pressure is reduced below a calibrated threshold, the fuel door is unlocked and refueling can begin. The FTIV is de-energized after the fuel door is closed.
The Powertrain Control Module (PCM) controls the FTIV operation through a low side driver control.