I have about 55k miles on my 2016 CMS4. Was out running errands with the wife and had the gas gauge at 4 bars. When we came out from a store and started it up, noticed it was at full tank. While I was hoping that some good Samaritan had filled the tank while we were shopping, I was skeptical :> Drove for a little bit and selected in the instrument cluster to watch the range, it was at full tank range and not changing. So, went to the gas station to fill the tank up, left it running to see what would happen? It filled up and as we drove away, noticed the range was now working and everything was back to normal. Very odd behavior but happy we had noticed it before running out of gas. Will have to keep an eye out for it, never happened before.

 

that is the start of your fuel level sensor going out. My car would alternate between full and a crack over half regardless of how much was in there. Working at a salvage yard I tried to find that specific piece but of course they'd never show up in any decent quality. I ended up buying a new unit from ECS and switching it out in my garage. Its fairly simple: pull the passenger side rear seat, flip a piece of carpet and remove the 10mm nuts holding a plate down, open the tank and swap the unit.

 

Thanks! I will have to start looking into it.

 

Paul, or #ECSTuning do you have to replace the whole fuel pump/filter/level sensor as an assembly and also are there special tools or things to know when doing it? I noticed a special tool from ECS to take off the cover of the tank, is this only needed for some models or needed for ours, I am guessing you have to connect a duel line or something to the new pump also, is there a special tool needed for that also?

 

Did it all today and it was a Breeze. I bought the Locking Ring tool but no special tools needed for the fuel hose clip on top of the pump. Everything is working again!