The info I looked at was for 5.3L vin B, single tank. The gage will default to empty if, the pcm detects a problem with sending unit circuit or if the ipc detects a problem with class 2 data from pcm.
You may be able to check gage reaction with resisters, get about three, 250 ohm--empty, 140 ohm--1/2 tank, 66 ohm--full tank. If the gage reacts correctly to each resister, I think the problem is the sending unit in the gas tank. If it doesn't react correctly could be a problem with pcm--ipc or wiring circuit.
The wire colors for the sending unit are black--ground, dark blue-- voltage. If you use a resistor between those two wire colors, key on, no need to start it, the gage should react. The voltage is a 5 volt ref circuit from the pcm.
You can get resisters from radio shack, don't cost much. You can also check for applicable trouble codes. Some of the national brand autostores will check codes for free. I just don't know if they will check manufacturer specific codes?
Tuesday, June 3rd, 2014 AT 3:39 PM