EVAP System Function Test
Vehicles with High-Voltage System
- In electric driving mode the Tank Switch-Off Valve -N288- -4- closes the breather line -6- to the EVAP canister -2-, so that it is not overfilled with fuel vapor, for example, when driving in electric mode for multiple days in a row.
- Because the pressure in the fuel tank -3- increases due to temperature effects when the breather line is closed, the Fuel Tank Pressure Sensor -G1169- -item 5- monitors the pressure inside the tank and causes the Tank Switch-Off Valve -N288- to open via the engine control module at a gauge pressure of 0.3 bar (4.35 psi). Additionally the valve opens when the fuel filler door release button is pressed, so that no fuel can squirt out of the filler neck when opening the cap to fuel.
1 - EVAP Canister Purge Regulator Valve 1 -N80- to Engine