The diagnostic start on this would be to check for DTCodes, there is a code for the sending unit, is the check engine light on? The gauge is controlled by the float in the gas tank. I would start at the tank with the float/sending unit. With a multi-meter check the resistance of the unit while moving the float up and down. Considering all the information for the dash gauges is send on a data wire from the ECM and its only the fuel gauge acting up. Start at the tank, make sure the ground wire has low resistance also. Here is a wiring diagram to help (wires are highlighted in yellow). I have seen many sending units in the tank go bad. Hope this helps.
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Monday, October 10th, 2016 AT 4:08 AM