E39 Key Fob Doesn't Function

[nooaaahhhhhhh]

Just finished bringing my 540i to life a little while ago and the buttons on both keys haven't worked since the car died in about 2010. I assumed that the batteries were dead and that replacing them would solve the problem so i did just that. I cracked open both keys, melted the solder points, pushed the old battery out and soldered on an exact replacement. Unfortunately it didn't work. Not only does neither key work, but they also don't initialize and trust me, i've tried every single possible way of reprogramming them. My question is: is there something in the car itself that could be faulty or is it the circuit boards and do I just need to bite the bullet and replace the keys??

Thanks
-Noah

[Driiven]

I can make you new keys if you need them done. I offer this service for members on here very cheap because everyone seems to like to gouge us. PM me if you need help.

[jclausen]

If you manually lock the car with the key and everything locks and the car beeps like when using the remote then it's a key issue, if your lock or unlock the car and only the drivers door responds the the system in the car is having an issue, check the fuse box in the passenger side of the trunk and the 7.5 amp fuse if it's blown try a new fuses then test the system if it blows again either right away or a hit later then the gas door lock actuator is probably shorted. As far as the key I cut mine open only to find the voltage on the battery was 3 volts, which is perfect. Then I initialized the curcuit board to the car and locks are working fine. I think it has to do with the travel of the button pin pushing in the worn micro switch. I plan to make the pin a bit longer and then test.

[sleuth255]

Do they start the car? Assuming yes. Assuming you also followed the below procedure to initialize all keys. Have you checked to see if the new batteries are charged? Drive around for a while with one then try to initialize it again.