This code keeps coming up on my truck. 2009 suburban LT. 5.3 FLEX. Just basic research showed its a fuel tank pressure sensor located on top of tank attached to the pump assembly. As luck would have it, I needed to change my fuel pump anyway. I dropped the tank and replaced the pump. The new pump already has a new fuel pressure sensor..so all good there. Put it all back together, drove it a couple of miles, and the code came back. P0452.
Any thoughts on what to check? Truck runs fine aside from that. No rough idle. No gas leak or smell of gas.

 

. unplug the connector and key to run...if the code goes to circuit high the fault is most likely in the new sensor. if the code stays circuilt low...either the wiring is shorted to grd or the pcm is bad. ohm check the wiring...unplug from pcm...check continuity and short to power and grd. if ok...suspect pcm.