I know it's been a while, but I just thought I'd update.hopefully it helps, keep us posted!
I had an issue with my Fuel Gauge reading incorrectly. Replaced both fuel pumps, sending unit, etc. The dealer wanted to replace the entire Instrument Panel, but I refused. I was tired of having them throw parts (and my money) at the problem without resolution. So, I traced all the fuel wiring using the factory service manuals, and found that some of the wireing went through AC Amplifier Unit. The part number is 27760-3FY6A. This solved the problem. I paid about $40 for the used part, and spent about 20 minutes putting it in (It's right behind the center console).
So, if you're pulling your hair out with the same issue, don't hesitate. It took me almost a year, and $1500 in parts to come to the conclusion that the techs had no idea of what they were doing, and fixed it myself.