I can't fill my tank.

Right, I wasn't suggesting the pressure sensor being the problem ... I was just suggesting that in your troubleshooting process, you might find yourself wishing you could observe what happens to the pressure as you are filling the tank, and hey, there's already a pressure sensor there for you to read.

What might be most interesting is a comparison to what you see the pressure doing in a known-working Prius while it is being filled.

Techstream is the easiest choice; you'll get repeated snapshots of the pressure reading, as Techstream repeatedly polls the ECM asking for the reading again. If that's good enough, it's super easy.

If you find yourself wanting to see quicker changes in the pressure reading, that's when you might think of hooking a meter or chart recorder directly to the sensor output. There will be pins back at the tank that might be hard to access, and of course pins at the ECM connector that might be easier to get at, and possibly pins at some intermediate wire harness junction that might be easier still. You can look in the wiring diagram to find those:

Toyota Service Information and Where To Find It | PriusChat

 

All I want to do is blow a controlled amount of air around the bladder with a couple gallons of gas in it five let's say I want to blow around the bladder and see if the vent valves are in fact letting the air out and or are they electronically controlled Is there some computer that has to turn that valve on by a sensor that's in the area between the tank steel and the bladder it reads a certain amount of pressure to open . I can almost taste this scenario with these cars just like the flooding of the cat you know anything to add an extra sensor and some rubber and what have you especially to the US market we get we get the guinea pig nonsense