2000 Toyota Camry LE Problem (Gas Tank or Sensor Problem?)

Hello,

I am hoping someone in this newsgroup can offer some ideas to help
figure out a problem
that persists with my 2000 Camry LE, which has the V-6 engine.

Whenever I try to fill up the gas, the pump automatically cuts off, as
if the tank is full.

This problem even persists when the tank is completely empty.

I have been to one auto repair shop, and they recommended I replace
the gas cap.

I did that, but to no avail. Hence, I have the following questions:

1. Could there be a blocked line or vent hose to the gas
tank, for
example, that is sending a false signal to the gas
pump, regarding
regarding its level of fullness or air pressure?

2. Is there some type of electrical valve or switch that
may need
to be replaced? (If so, please specify the name of
part.)

Thanks in advance, for any help that fellow Camry owners or Toyota
Technicians may
be able to offer in helping to solve this nuisance of a problem.

Kind regards,

Glen E. Sarkis