03 Yukon 2500 8.1ltr fuel pump

[95 S_Trucker]

The filler neck goes to the rear tank. Then there is a big filler tube between the rear tank and the front tank. There is also a pump in the rear tank that will pump fuel into the front tank. The rear tank is used like a transfer tank. The computer looks at the fuel levels in each tank and it will decide when the rear fuel pump runs. It will also send a signal for the fuel gauge.

All 2500 suburbans from 00-07 have 2 tanks.