[JCMech]

Well summer is here, and my 2011 535ix stopped responding to the key fob when it gets hot above 25C. Door locks did not respond to the lock or unlock button, nor the trunk to the remote.

Interestingly, I found that it started working after the sun goes down or if I park it in an enclosed garage or when the temperature cools down.

I got a new remote battery but it did not make a difference.

It got so bad that it only works when I leave it overnight in my garage.

Some posts mentioned that its the diversity antenna, so I ordered a used one and yes it started to work again.

A few weeks later it stopped responding and failed.

Called BMW, found out that its the same module for the 5, 6, and 7 series and a new one goes for $570CDN! plus installation.

So I gave repairing it another shot - brought my old original one to a friend who rebuilt it. Reinstalled it and left my car on my driveway in the sun for a week of 30C+ and all is working fine!!!

No more worrying about whether it needs coding as I now have my original one repaired and back in the car.



Hope this helps troubleshoot why the keys do not work only during our hot days!