[pen15ofgoldd]

I am not able to open the trunk since the battery is drained. I have an appointment to take my car is tomorrow morning and need to remove my jb4. So will it be safe to just pull it out since the car has no power at all?

[Rob_BMW_PNW]

Yes

[OneMoreAlex]

Originally Posted by pen15ofgoldd

I am not able to open the trunk since the battery is drained. I have an appointment to take my car is tomorrow morning and need to remove my jb4. So will it be safe to just pull it out since the car has no power at all?

Yes, but I'd recommend connecting jumper cables or a battery charger using the positive terminal and ground in the engine bay to allow access to pop the trunk. Then disconnect the battery like normal.

[pen15ofgoldd]

will this also start my engine or only give enough to allow me to pop the trunk?

Originally Posted by OneMoreAlex

Yes, but I'd recommend connecting jumper cables or a battery charger using the positive terminal and ground in the engine bay to allow access to pop the trunk. Then disconnect the battery like normal.

[OneMoreAlex]

Originally Posted by pen15ofgoldd

will this also start my engine or only give enough to allow me to pop the trunk?

As long as you don't put your foot on the brake when you press the start button with the key in the ignition, it will only power on the electronics so you can pop the trunk. Although, it should start unless the battery is just completely shot.

[weehe126]

there's no point in giving power to the battery to remove the JB4. You can remove it without disconnecting the batter as long as the car is asleep. In this case, the car is asleep...

[OneMoreAlex]

Originally Posted by weehe126

there's no point in giving power to the battery to remove the JB4. You can remove it without disconnecting the batter as long as the car is asleep. In this case, the car is asleep...

Well, actually there is a point. You're giving the car power to pop the trunk and disconnect the battery. Why not take two seconds to disconnect the battery for peace of mind? There are plenty of things that could wake the car from sleep mode and provided one small electrostatic shock that could potentially fry your DME. For me I would never leave it connected even though you "could", especially since it's something so easily avoidable.

[pen15ofgoldd]

i want to clear codes before i take it to bmw.

Originally Posted by weehe126

there's no point in giving power to the battery to remove the JB4. You can remove it without disconnecting the batter as long as the car is asleep. In this case, the car is asleep...

[weehe126]

Originally Posted by OneMoreAlex

Well, actually there is a point. You're giving the car power to pop the trunk and disconnect the battery. Why not take two seconds to disconnect the battery for peace of mind? There are plenty of things that could wake the car from sleep mode and provided one small electrostatic shock that could potentially fry your DME. For me I would never leave it connected even though you "could", especially since it's something so easily avoidable.

If the battery doesn't have enough power to open the trunk, it wont have enough power to fry the DME...

[weehe126]

Originally Posted by pen15ofgoldd

i want to clear codes before i take it to bmw.

JB4 can't clear all codes. You would need INPA for that. You will also need a full charge battery then. However, pretty sure a dead battery/disconnecting resets any code.

[OneMoreAlex]

Originally Posted by weehe126

If the battery doesn't have enough power to open the trunk, it wont have enough power to fry the DME...

Agree to disagree. There's still an output of power regardless if it's making 12v. Although I'm sure it would be a very rare situation, it's still a slight risk that possibly can cause a problem. Like I said I wouldn't take that risk over something so silly.