I have a 2011 GMC 2500HD Denali with 6.0 ltr. Filled up a while back and fuel gauge didn't go quite to full. Later on it dropped to E. I changed the sending unit in a rush situation and it still doesn't work. So I've decided to slow down and do a little troubleshooting. Read the codes and I have:
P0449 - evap vent valve malfunction.
P0452 - evap pressure sensor
P0461 - fuel level voltage signal
P0463 - innacurate fuel level reading
I am now wondering if I may have a connector issue being that the evap and level sending unit wiring is in the same harness under the truck and both of these issues happened at the same time. I don't want to left the bed or drop the tank just to test voltage. Does anyone know if there is a connector and where it may be between the computer and this harness? I would much rather troubleshoot voltage under the hood somewhere than on the connector on top of the tank.
