Hi,

I have a 1998 Deville that I am trying to stop the P0452 code from coming up so I can pass emissions testing.

The code P0452 is apparently "Fuel Tank Pressure Sensor Circuit Low Voltage"

I used a scanner tool to read that the Fuel Tank Pressure Sensor (FTPS) is reading ~648 INs of H20( a little of 1.5 atmospheres) no matter if the gas cap is off/on, car running or not. I assumed this meant that the FTPS is bad since it shouldn't show that much pressure if I open the tank to the atmosphere.

I replaced the sensor by partially lowering the tank. Put everything back together and still getting the code with the new sensor and the same pressure reading out of the scanner.

So I am totally at a loss for what to do next. I assume I have some sort of short somewhere. Does anyone have a wiring diagram for the FTPS and/or fuel pump harness? I do not want to lower the tank again, because that was a BEAR of a job on jackstands...

Or maybe it is a completely different problem. I would appreciate any thoughts/solutions.

Thanks,
Have a Good Holiday,
Karl