belzebutt

I started getting a warning saying "please replace key fob battery", and I tried four different batteries and it still won't make the warning go away. I tried the second key fob that I never use and it does the same thing. Is there something I should be doing? If I put it in backwards it doesn't work at all. I even bought some new Maxell 3V CR2032 batteries and it's the same thing.

synergize

Reset the MMI, if that fails, try OBD11 to find and clear the fault. There is also a setting in the MMI to select number of remotes being used, give that a try too!

georgeg02

I have the same issue with my 2019 RS5 SB. Replaced the battery and still get the replace battery warning.

MH62

Just replaced my battery two weeks ago and the warning disappeared immediately. One thing I learned in the process is the keyfob LED stops operating when its battery is too low. If your keyfob LED turns on with key presses, then the issue is the car. If not, it's the keyfob.

belzebutt

So after I replaced it with a Maxell it was giving me the warning again, and then I decided to open/close all the windows and doors a few times by holding down the fob buttons. The last few times I tried starting the car it didn't give me the warning. Let's see how long that lasts.

georgeg02

Issue solved!

The battery compartment was not completely seated. One I removed the mechanical key and properly seated the battery compartment the message was gone.

BlackOptic

Ugh. It was time for me to find this thread...

...because same thing.

BlackOptic

...I’ll try the window up / down thing next.

MH62

Is you keyfob red LED turning on when you press a key?

BlackOptic

Yup. Got the red flashing LEDs. I mean, the fob works fine opening rear hatch, locking/unlocking the doors.. etc.

But, i just installed a fresh battery and the low battery warning is still there.

No issues with the second fob (which I never use).