Key fob battery replacement

[Jimbo's M]

It feels so nice in your hand. All the little markings are raised, my old key is worn smooth like a marble.

Funny, but true. When I replaced mine years ago, it instantly reminded me of when the car was brand new. Sigh...

[Kcalhoun27]

Just replaced my key as well. Followed the instructions and my door locks are working once again. Doesnt get easier than that.
It feels so nice in your hand. All the little markings are raised, my old key is worn smooth like a marble.

[sapote]

I don’t think that’s issue since one key was working and the other wasn’t at one point. I kinda figure after 19 years these things might die at some point.

I still would try with a friend key before cut open to replace the batt.

[simon_c]

I don’t think battery or key is the issue here. You should try with other keys from any E46 cars - sync or pair these keys to your car and they should work; if not, the Car has RF antenna issue

I don’t think that’s issue since one key was working and the other wasn’t at one point. I kinda figure after 19 years these things might die at some point.

[sapote]

Looks like both the batteries on my key fobs don't work anymore. I?

I don’t think battery or key is the issue here. You should try with other keys from any E46 cars - sync or pair these keys to your car and they should work; if not, the Car has RF antenna issue

[Shonky]

Seems like you can crack it open and solder judging by what some of the other E46 forums say. But if you want a new key, much cheaper to buy an inexpensive aftermarket fob, get it cut (with your old one as template) then buy an AK90 and program it. And that way you can make however many fobs you wish

Got any recommended sources for keys? The key I got (10 odd years ago) I found works fine as a remote but does not charge. If I charge it externally it works fine. Also it always starts but occasionally there are codes about that specific keynin the EWS.

Note to others, you need to pull out the EWS module to do this. Not hard but needed. You can then just read it and program one of the unused factory codes into a blank key. I went this way so there was no need to actually write to the EWS ie less risk of things going pear shaped. Also you don't need to pull it again as long as you're just using the keys you read out. You just can't reuse any key IDs.

[Maxima SE]

This is probably what I’m going to end up doing. Just annoying that we can’t simply
crack the key fob open and swap out the battery for $5.

Yup... its dumb. On the E92 they fixed that for us. But they took away the oil dipstick. I got mine from BMWMINIPARTSTORE too.

[timmo]

Seems like you can crack it open and solder judging by what some of the other E46 forums say. But if you want a new key, much cheaper to buy an inexpensive aftermarket fob, get it cut (with your old one as template) then buy an AK90 and program it. And that way you can make however many fobs you wish

[simon_c]

Have you tried charging your keys with a wireless phone charger or electric toothbrush charger?

How would I go about doing that?

[simon_c]

I just bought one from thebmwminipartstore.com. $200 shipped and it showed up in 4 business days. Need to send them a photo of your registration and drivers license after ordering. It’s an entire new key.

This is probably what I’m going to end up doing. Just annoying that we can’t simply
crack the key fob open and swap out the battery for $5.

[meowth]

Have you tried charging your keys with a wireless phone charger or electric toothbrush charger?

[gouda]

I just bought one from thebmwminipartstore.com. $200 shipped and it showed up in 4 business days. Need to send them a photo of your registration and drivers license after ordering. It’s an entire new key.

[simon_c]

Looks like both the batteries on my key fobs don't work anymore. I did a quick search and looks like the battery isn't easily replaceable and requires soldering? Just want to see what the options are here. Hopefully it doesn't require going to the dealer to get a replacement (if so, do we have a general cost?) and is a replacement going to getting a new key fob entirely?