Remote key working intermittently

[Henn28]

Originally Posted by andrewwynn

I went though the same. I reflowed the solder on both my keys. They worked again for a while. Then they stopped.

The weirdest part was: key world work if I slammed the trunk but that even stopped working.

I eventually "bit the bullet" and ordered a real key from online dealer.

Fixed the problem 100%.

It was exclusively the key the entire time! I suspect the same in your case. The original keys have enough bad solder joints they aren't able to sync with the car anymore and the cheap copy just isn't up to snuff.

I was ecstatic when I finally just did it. Worth every penny to have a real key. There is an online actual legit BMW dealer that will save $60 or so. I bought a valet key with the savings.

Search xo for the thread on the subject. It has links to the exact part webpage.

I just need to do the same thing, buy new keys from BMW.

Thanks for this entire thread as I’ve been following it closely. Very occasionally my key will fail to work at all, however after I unlock the door manually with it, the thing starts working again. Sounds like the eBay/Amazon stuff isn’t worth the time for this.

[andrewwynn]

Originally Posted by Henn28

I just need to do the same thing, buy new keys from BMW.

Thanks for this entire thread as I’ve been following it closely. Very occasionally my key will fail to work at all, however after I unlock the door manually with it, the thing starts working again. Sounds like the eBay/Amazon stuff isn’t worth the time for this.

This was my exact symptom that led to me doing a reflow on my two keys.

If I locked or unlocked with the key blade the fob would immediately work for a few presses lock/unlock.

I could also get it to work after a battery jump start making me think it was possibly worn battery but after opening up and measuring battery = good I reflowed most of the solder joints and both keys syncd after that and worked for over a year