[Omar.bmw]

Hi everyone,

I have one original key that comes with the car when I bought it, I started having a message in the dash that the key battery is low so I decided to change the battery,
I researched and found a lot of people just opening the key fob and unsoldering the old battery and resolder the new one. Also, I decided to buy a new shell case for the key the black part in the picture, so I don't have to glue it as the original one comes glued.
So I decided to do it, and after I replaced the battery it didn't work at all like it didn't lock or unlock the doors or the trunk but it would start the car.
I tested the battery with a multimeter and it seems it giving me 3Volts which is fine so I decided to put back the old battery to see if it still works because it was working before I replace it and it doesn't.
I even tried to use just the chip without the case because I thought the case is pressing on something and still doesn't work
So any idea of where I messed up? or what is happening?
The original battery is a VL2020 Panasonic
The one I bought is ML2020 Panasonic
Even when I put back the old battery which was working perfectly is not working
Here's a video I followed of how to replace it that I did the same with no luck:

[ctuna]

Take the fob down to a place that can test that it's putting out signals
when the button's are pressed the problem may not be your Fob.
Can you start the car with the Fob in the Slot?
It would be also a good idea to get a spare as soon as possible.

https://www.e90post.com/forums/showthread.php?t=1510527

[Omar.bmw]

The car start when I put the fob in the dash slot, it's only the lock and unlocks and trunk release button that is not working.

[TunafishE93]

You knocked off a resistor. You can see the traces where the resistor should be are not the same as traces where nothing goes (usually a smooth bump).

Anyways its a zero ohm resistor or you can just bridge traces together with some solder.

[Omar.bmw]

Thank you so much for your reply,
I didn't go there at all because the soldering is on the other side, the resistor still there on the other side if you see the other picture that shows the other side of the board,
but I will double-check it you never know.

[TunafishE93]

More likely it was knocked off when splitting case. The other side is irrelevant in this case.

[PhaseP]

Originally Posted by TunafishE93

You knocked off a resistor. You can see the traces where the resistor should be are not the same as traces where nothing goes (usually a smooth bump).

Anyways its a zero ohm resistor or you can just bridge traces together with some solder.

Impressive that you caught that from pictures!
The video OP linked shows a resistor at that place indeed.

[Omar.bmw]

Yes, Thanks a lot TunafishE93 you really found it, I was able to solder it together and it worked! my goodness!

[Converted1]

Just want to give a massive shout out to TunafishE93 for this solution. Somehow my resistor got knocked off as well when I was splitting the cases even though I was super careful. I bridged the terminals and the remote started to work again! Thanks!

Originally Posted by TunafishE93

You knocked off a resistor. You can see the traces where the resistor should be are not the same as traces where nothing goes (usually a smooth bump).

Anyways its a zero ohm resistor or you can just bridge traces together with some solder.

[JakGfx]

Originally Posted by Converted1

Just want to give a massive shout out to TunafishE93 for this solution. Somehow my resistor got knocked off as well when I was splitting the cases even though I was super careful. I bridged the terminals and the remote started to work again! Thanks!

Hello, maybe I’m a little late, did you use any flux or anything, am I safe doing like you did? It’s the only key I have and the battery is dead from long time, did you use superglue to close the key again?

Much appreciated

JakGfx

[Converted1]

I used a replacement snap together case from Amazon. They fit really well and look oem. Here’s the link.

https://www.amazon.com/dp/B084WSN9C9...n_title_1&th=1

I did not use flux, I carefully bridged the spot with solder.

Originally Posted by JakGfx

Hello, maybe I’m a little late, did you use any flux or anything, am I safe doing like you did? It’s the only key I have and the battery is dead from long time, did you use superglue to close the key again?

Much appreciated

JakGfx