How to Repair BMW E46 3 Series Remote Key

by | Aug 20, 2022 | Articles


Im going to show you a technique I have tried. This is actually a new battery and  has the soldering points on it already. It comes packed on a piece of polystyrene ready to go and as you can see it has the housing on it already. You don’t have to solder the housing. You can see the two points they just slot into the current soldering points on the board. I’ll show you a close-up of those so you can see that there’s obviously a positive and a negative terminal there. This makes it really handy when you’re replacing this battery. What you need to do is to get this key open. I’m just going to show you the best technique of opening it. Be really careful I don’t want any injuries.

The top tip is to go into the top end here it’s a weaker point of the key. You can just push down you see the blade sort of chops that first area off and then you can sort of slide down and take the key off but again just to reiterate be really careful when doing this it gets a bit tricky when it gets to the key area when it gets to the actual bottom area so be really careful and then you can prise it open and you will see the board will actually be attached to the button end so it won’t actually fall apart as I’ve shown here but you can then just take that off easily it’s not if it’s not secured in with any glue or anything and then you have your component parts so here you can see the board and the micro switches and you have unlock button you have the lock button and the boot release so here you can see the two soldiering points that the battery will go into there at the very top left and right and then turning over the key you can see these solder points the battery is almost a like-for-like switch so essentially what we’re going to do is release the solder points and then the battery cage with battery should just  pop off okay so here we are with the soldering iron to do is weaken those two solder points and to enable the battery to come up you so there we have the battery has been released from the board you and that’s what it looks like without the back you and here’s the new battery as you can see it’s almost identical to the old battery which is really helpful as before the batteries just come on their own so they don’t have anything caged on there but with this one you just simply just slot it into the holes there and then it’s a case of dubbing either additional solder on there just to be safe or you can use the current solder that’s on there at the moment so there we have it we’ve got the new battery soldered on to the motherboard and my sole rings are not particularly brilliant so take it with a pinch of salt but there we go the cage isn’t ready to go it’s securely on what I would recommend now is go out and test it so before we seal this unit back up just go and test that the soldiering is all nice and strong you’ve got a strong connection and the key should function correctly we’ve put the new battery on and we’ve sold it in place and we’ve tested it out now it’s a case of fixing it back together so I would recommend just clean up the areas a little bit because the plastic it doesn’t cut particularly well clean it out they’re going to be all sorts of grime and dirt in there from 15 years of carrying it around in your hands and pockets so just get rid of that make it as clean as possible so on the first key I tried a few options of fixing it together now I  tried superglue that didn’t work very messy and made quite massive it made a big mess of the key so what I’d recommend is a product cord sugar I came across is quite a while ago it’s really handy for this purpose you can check out their website below to see what other things you can do with it so essentially sugar root is a moldable glue which is really helpful when we’re trying to put this key back together because we kind of wanted to squidge in all the areas that we’ve just cut out obviously if it’s a sealed unit before hand we want it to be fairly sealed when we put it back together so this is sugar have a read up about it it’s safe to use on your hands so you don’t need any gloves you can just use tissue paper to wipe it off and sugar is a little bit like plasticine so you can mold it you can shape it so if you roll it roll it out and then just start beating it around the edge of the bottom plate of the key create a nice seal so just sort of squidge it down you so here we have it two keys we battery’s ready to go hopefully for another 15 years have any questions put them in the comments below and you can also find the links below to the battery with the housing and also sugar you can have a look on their website you can purchase your guru from Amazon or direct from the manufacturer and thanks for watching.

Related: BMW E46 engines for sale 



Drawing from extensive expertise in the used car parts industry, Craig Sandeman has established himself as a trusted authority in automotive repair. He possesses a deep knowledge of the challenges encountered by individuals seeking reliable car parts, making him a highly sought-after expert in this field.


Potential issues, causes, and solutions have been identified in the above article based on the experiences of car owners and repairers, as well as web materials such as forum blogs and technical support bulletins. This data is supplied exclusively for the purpose of reference. Only appropriately qualified persons should perform repairs and/or changes on your vehicles.

While it’s important to keep in mind, it’s also important to note that the amount of times anything is mentioned here should not be seen as a sign of its reliability or frequency. Various owners, driving in different ways, and caring for their vehicles in distinct ways will cause two identical vehicles to perform differently.

As previously said, this material is supplied primarily for reference reasons; nonetheless, we hope that by doing so, we will be able to supply you with essential knowledge that will allow you to make informed decisions whenever you encounter any of the aforementioned setbacks.


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