Hi Vladimir,

Here is a response to my post some months back from Abe Crombie:

The fuel tank test pulls a vacuum on the tank. The 611 code is for a large

leakage. The pressure sensor on tank just measures the pressure and the

control unit monitors the pressure during the vacuum phase. The control unit is programmed to identify large leakage if the pressure sensor doesn't report lowering pressure when the control unit operates the fuel vapor canister purging valve to apply this vacuum to tank, lines, and canister.

This can occur if the purge valve is not opening fully on its repeated

operating cycle during this test, if the canister fresh air vent valve is not closing during this phase, if the gas cap is leaking or is not sealed, if the vapor canister is plugged up, or if there is a leak anywhere on the tank or lines. Your dealer needs to investigate more and quit blaming you if you have certainty that the light has not come on when the fuel cap was loose.

It fixed my problem and I hope it does yours.

Brian M.