Odb2 Code Po452

Hi there, I have a chevy venture a 98 model and the mil is on the code is PO452-EVAP system pressure sensor signal low. Also on the same van my fuel guage does not work properly it has a mind of its own it goes back and forth. I have cleared the code but it comes right back, can anyone help?

This place is a little weird. As soon as I get a problem, someone else posts that they have the exact same problem. If you can give me a day or two, I might be able to help you out more if I can figure out what is wrong with mine.

Your screwy gas gauge is a result of a resistance that isn't between the correct range. Normally the resistance from the sending unit should be from 40-250 ohms if I recall correctly. If it reads too low or two high, it will indicate full when first turned on and then drop slowly to empty.

About a year ago, I replaced the fuel pump/sender as well as repaired a broken wire. I presumed that the wire was broken initially when it first started having a problem about a week ago, so that was actually the first place I checked. The repair was fine, so I checked the resitance with the tank about empty. It read 38 ohms which is close enough. I filled the tank with about 5 gallons, enough that I should get a higher resistance, but then the circuit measured a short, 0 ohms resistance. This makes no sense for the type of circuit. So I think I might have to do some more investigating and possibly drop the tank.

As to the EVAP P0452 error code, I too am getting this. Traditionally, the first thing to always check on this is the gas cap. If it doesn't seal right, it can throw the error code. The fact that it always comes back instantly the next time leads me to beleive that it may not be that in our case. I haven't looked into that at all and so once I read up a little in the shop manual, I can tell you more.

I'm almost wondering if the two problems are related...say a common wiring harness or connector that has gone bad. Donno though.

Hi there, I have a chevy venture a 98 model and the mil is on the code is PO452-EVAP system pressure sensor signal low. Also on the same van my fuel guage does not work properly it has a mind of its own it goes back and forth. I have cleared the code but it comes right back, can anyone help?I'll be waiting in the main time a friend told me about the evap line under the hood that has to maintain 1psi at all time. I saw this line next to the air filter duct the only problem is how do i applied 1psi to such a line, how do i measure 1psi? I was also told that there's a pressure sensor at the fuel tank. I hope these information help some.

I think cdru is on the right track. The 00 service manual diagnostic chart shows this code to be either a bad connection at the fuel tank pressure sensor harness or downstream at the PCM, or a bad fuel tank pressure sensor. Checking these things will be no easy task since you'll have to drain and drop the fuel tank to get at the sending unit. I hope it's nothing more than a loose gas cap. Fjag27 symptoms almost certainly sound like a bad connection somewhere. Regards, gb

The voltage should be between .1 and 4.9V. If the voltage is below .3, the trouble code is set. The wires should go through the same connectors where the fuel pump and sending unit are located, beneith and slightly behind the driver's seat. But don't quote me on that location.

The voltage should be between .1 and 4.9V. If the voltage is below .3, the trouble code is set. The wires should go through the same connectors where the fuel pump and sending unit are located, beneith and slightly behind the driver's seat. But don't quote me on that location.

Thanks a mil. am going to check that out, by the way was that the problem with yours?