I have some experience cutting open two of my keys to reflow and replace one of the batteries.

I was successful in both keys even repairing the one I drilled through a trace.

That said after working about two years one was lost and the other stopped working.

I can't risk reflow again on my only key so I'll be getting a factory key when I get tax return then I will open up my key and reflow it again.

You should check the battery on your primary key then measure it while pressing each button to confirm the button switches are working.

Then: figure out if the roof window switch is your problem you can maybe jumper the switch to convince the car it's closed. (odds are that will be tricky BMW uses hall effect sensors not micro switches usually.

The clown nose is the red hemisphere on the bottom of the rearview mirror and when alarm is set the nose flashes.

You can confirm if the alarm is working a couple ways:

1. Open hood, press the hood switch, lock the door with key (helper), release hood switch. That should set off alarm.

2. Leave a door or trunk open, lock driver door with key, close door. That should make the corner lights all flash to confirm alarm set.

I'm pretty sure alarm will set with roof window open so unsure that will help you I'm thinking monitor the roof open sensor and open/close a couple times see if you can set it to close and start key sync.

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2011 E70 • N55 (me)
2012 E70 • N63 (wife)