Calling anyone who has swapped a 2004+ engine into a 1998-2003 rig

[Nak]

From 1998 till somewhere around 2004 GM fuel senders were 40 ohms empty and 250 ohms full. Then they reversed it to 40 ohms full - 250 ohms empty.

I swapped a 2012 L94 6.2L into an older rig. The L94 ECM--E38-- has a 2011 OS on it for various reasons. Here's my problem: The fuel sender reads 40 ohms empty and 250 ohms full; that's reversed from the 250 empty normally seen after 2004. I can see how to calibrate it in HPtuners, but will the reversed fuel level curve be compatible with the ECM? Or will the curve being reversed cause problems?

Thanks!!

[Ray@NP]

you can use the factory fuel gauge and sensor for the truck you are doing the swap to, just run the wiring from the chassis harness up to the cluster and the fuel gauge should work, there is no need to run it through the ecm

[Nak]

Actually my plans require the ECM to get the fuel. My truck is a '92, and the factory gauge won't work with the '98 fuel sender. (I ran a '98 tank to get a fitting for the vapor pressure sensor and a 40-250 ohm sender.) I plan on running three android tablets as flat panel displays in the truck. One for the gauges, one for Navigation & Data, one for music. the last two will be interchangeable as far as functionality. Gauges will be run off the ALDL port, so fuel level to the ECM is important. If that doesn't work I'll have to change my plans dramatically.

[Nak]

Okey dokey, I flashed a new tune with a basic linear fuel sender calibration reversed from normal. Then I hooked it up with multiple resistors and varied the resistance. HPtuners shows the fuel level proper for every resistance, so the fuel gauge should work fine in reverse. Hopefully fuel mileage and distance to empty calculations will work with the reverse curve.