[Midtown2020]

I disconnected the negative terminal on my battery then closed the trunk hatch. Now I can't unlock it as there is no power to the lock actuator. Car doors are unlocked so I climbed in the back and tried to find a manual release but didn't see one.

I tried connecting a jump starter battery to the positive terminal and ground terminal under the hood to give power to it. The only sign that there was any power going though the car was a small light on the interior of the lift gate. I think that is on because the lift gate itself was not fully shut, just enough for it to latch. Anyway, no other sign of the car being powered.
Key fob won't work, door release at hatch or at driver armrest doesn't work.

I'm in a catch 22. No power to release the trunk hatch so I can reconnect the battery so I can have power

How can I get that trunk unlatched? Why aren't any of the systems powering up when I connect the jump starter battery? Did I pop a fuse? Which one? Is my 12v jumper battery not sufficient?

I'd appreciate any advice or solutions! Thanks in advance...

[BMWZ4]

freshxdough are you able to help this member? I've heard of a solution but couldn't find it after a search here

[jmh]

Not sure if this is applicable to the F97, but worth a shot

[Midtown2020]

Originally Posted by jmh

Not sure if this is applicable to the F97, but worth a shot

Thank you for your help!! I will check if that hole is there on my F97 out of curiousity. In my case the cover panel over the under floor area was latched shut and I don't think it can be lifted when the door is closed. I appreciate you posting this for me.

[Midtown2020]

I ran to Autozone and bought jumper cables and a beefy battery charger. I used the jumper cables with my M2 and was able to get it powered up enough to unlatch the hatch and reconnect my battery! Everything works fine, I was scared I fried some fuse or worse an electronic module.

Crisis resolved! Now I can enjoy my new carbon fiber shift paddles!

[freshxdough]

You need a 12v jumper to actually boost the car to 12v. Some jumpers have a button to bypass the "low voltage" of a dead battery and push 12v. The jumper is basically seeing 0v which is what it sees all the time. Even just sitting there disconnected. A 12v power supply that is feeding 12v will give your car power

[2kaccordocoupe]

If you were already in the car why not just re-connect the battery? What am I missing here?? What does opening the hatch have to do with connecting the battery.

[Midtown2020]

Originally Posted by 2kaccordocoupe

If you were already in the car why not just re-connect the battery? What am I missing here?? What does opening the hatch have to do with connecting the battery.

The battery is under the floorboard, which is in itself a lift hatch also, which is hinged near where the rear seats are. If you try to lift the floor board from within the car it lifts upward toward you and the ceiling. This effectively creates a wall between yourself and where the battery is.

It’s designed to give good access to a user behind the vehicle when the lift gate is open, not to someone accessing from within the car.

[2kaccordocoupe]

Originally Posted by Midtown2020

The battery is under the floorboard, which is in itself a lift hatch also, which is hinged near where the rear seats are. If you try to lift the floor board from within the car it lifts upward toward you and the ceiling. This effectively creates a wall between yourself and where the battery is.

It’s designed to give good access to a user behind the vehicle when the lift gate is open, not to someone accessing from within the car.

The floor comes out.

Here is a stock photo, see where the 2 black plastic things are on the trunk floor where it meets the folding seats. Those both pop up with your fingers. You will see a small screw under each. Remove those two screws which is the hinge and the whole floor comes out.

[spta97]

Originally Posted by 2kaccordocoupe

The floor comes out.

Here is a stock photo, see where the 2 black plastic things are on the trunk floor where it meets the folding seats. Those both pop up with your fingers. You will see a small screw under each. Remove those two screws which is the hinge and the whole floor comes out.

Just as an FYI for those who may need to do this, these are TORX bolts (forgot the exact size but rather large) so make sure you have the right bit for your socket wrench.

I don't think a screw driver could take these out as they are torqued in pretty good.