I have a 2012 G37xS coupe. Recently my gas gauge has been stuck around 2/3 even when the gas is lower. It will go to full when I fill up but it's obviously not reading right.

I read here that it could either be the fuel sensor or the AC Amplifier module.

It seems most people find success with replacing the AC Amplifier. My question is how to do know which part number to get? Is there somewhere I can search online for my car? I know I could take apart the dash to find the part, but was hoping I could just order the used part first so I only have to open up my dash once to replace the part. I really appreciate any help on finding the correct part number. Thanks!

UPDATE:
So I finally fixed it. The issue was the AC Amplifier Control Module. For anyone who stumbles on this thread here is the info:

The part number needed is: 27760-1NM6D
However they made an updated version which fixes the fuel gauge issue from happening again, that part number is: 27760-1NN2A

I bought the newer version of the part on ebay, used, for about $90. Brand new the part is around $700.

You can go to this website and put in your car info to check what model number you need for your car (that is how I discovered there was a new model of the part): https://www.infinitipartsdeal.com/

This video on YouTube shows you exactly how to remove and install the AC module:

 

Any updates?

 

I cleaned the physical fuel sensor that is behind the passenger seat, under the back seat. That didn't solve it. I still didn't get around to trying to replace the electronics behind the dash. I've just been monitoring my mileage in the meantime but I plan to order that part soon.

 

the best way to tell is pull your current one out and write down the number on it

 

So I finally fixed it. The issue was the AC Amplifier Control Module. For anyone who stumbles on this thread here is the info:

The part number needed is: 27760-1NM6D
However they made an updated version which fixes the fuel gauge issue from happening again, that part number is: 27760-1NN2A

I bought the newer version of the part on ebay, used, for about $90. Brand new the part is around $700.

You can go to this website and put in your car info to check what model number you need for your car (that is how I discovered there was a new model of the part): https://www.infinitipartsdeal.com/

This video on YouTube shows you exactly how to remove and install the AC module:
TIP: Make sure you disconnect your battery before doing this install or you'll get an airbag warning light. If that happens you need to reset it via the OBDII or unplug the battery.

 

Yep, called it. Good to know the new version works. I have a spare old version sitting in storage just in case lol.

 

My friend has a 2013 with the new updated part from the factory and his went bad and he needed a new one. We just got it from the junkyard. So the the updated part isn't fool proof. And no need to disconnect the battery, if you don't want to. Just follow these steps.

1. Turn the ignition ON, but do not start the engine.
2. Wait for the airbag light to come on and then go out (turn solid, then off).
3. As soon as the light turns off, immediately turn the ignition OFF.
4. Repeat this sequence (ON/OFF) three or four times.
5. On the fourth cycle, start the car, and the light should stay off.