Key fob trunk pop button not working

[stalcup550i]

2008 550i everything else on the key fob works fine except trunk. Trunk opens fine if I open with hand by placing my hand under the lid and it then pops all the way up. Also, the trunk release button inside the car works fine when pushed, pops the trunk all the way up. I know the button seems to work fine because if I hold down the trunk release button for a few seconds the alarm goes off. Any ideas?

[chris097]

I had the same issue when I first brought home my 2007 E60, I found I was either holding the trunk pop button on the key fob too long or too short. try to hold it for just about 2 seconds and then let it go. After figuring that out now I'm practiced to where I can get it every time. That said, I did replace my key batteries the day after I bought my 07 530xi (one was dead) and this greatly increased the range for me. they are pretty standard CR watch batteries and you can get them in a Radio shack.