Question

How do you fix the p0651 code on my 2005 Chevrolet Avalanche 3.5L? fuel tank pressure

Answer 1

P0651 is 5 volts to either the fuel tank pressure sensor or the a/c pressure sensor, when it comes to the Chevy Avelance, if you are setting any EVAP code your dealing with the FTP if there is no EVAP code there you can suspect that the a./c pressure sensor

Answer 2

P0651 CHEVROLET Code - 5 Volt Sensor Reference 2 Circuit
Read more: https://www.autocodes.com/p0651_chevrolet.html