[Pittsburger]

So I was trying a battery disconnect (after my charcoal filter removal) and all hell has broken loose.

First, I dropped the wrench that comes with your BMW. It falls below battery. I can't get to it. So I say forget this I'm quitting.

Then upon trying to quit and put it all back together I noticed a wire is loose. But I didn't pull anything out.

To make matters worse that long nail from the plastic barrier on the side of the battery - it can't find the screw in point.

I've attached a photo of the loose wire.

Any advice out there for those who have successfully removed your battery?

[ctuna]

Its some kind of battery maintenance cable .
did you go to the DIY section and read the battery replacement procedure.
do you have a magnetic retrieval tool hopefully the tool you dropped is magnetic.

http://www.e90post.com/forums/forumdisplay.php?f=16

sorry I got the wrong link the first time

Why would you dissconnect the battery for a filter removal/change ?

http://www.e90post.com/forums/showth...hlight=battery

[braveplayer3160]

Slow down cowboy! By your terminology I take it you have not wrenched on cars that long. If that is the case the key is patients. Lots and lots of patients. When things aren't going your way, sometimes the best thing to do is walk away for a bit and come back too it later with a clear head. With that being said...

1. The wire that is "disconnected" is the battery disconnect for shipping purposes. Without going into detail... It's not plugged into anything or needed.

2. Unbolt the battery cables (Wrap the ground with a ziplock bag and put a rubber band around it so it cannot accidentally connect to the battery again) remove the battery and get you wrench. Dont leave it down there. (If you are not sure how to get the battery out use the search function. There is a great write-up that details this)

3. With the battery out of the compartment look at the battery hold down mounting location "that long nail from the plastic barrier on the side of the battery" you should be able to figure out how it mount to the battery tray and then to the battery.

Take your time and everything will be fine. I myself have not worked on bmw's very long bt if you read and do some homework yo should have no problem doing the basic maintenance on these vehicles.

[Pittsburger]

So I took the wise advise of my two responders and completed the mission.


For my fellow amateurs, I give you my notes:

First, in response to a question: I wanted to detach the battery after my charcoal removal since some people report that it resets the driving behavior whatever on the computer or something rather. (So I have no idea, but this sounded right and the downside I hear is that you just have to reset the clock.)

If you are confused as what the connection to the negative terminal looks like, it is attached.

This is helpful in understanding how the node gets de-tached. Since I saw a youtube video of a guy saying you don't have to unscrew the nut from the bolt to disconnect the negative terminal from the connection.

Also, I attached some pics of my fallen hero, the wrench. He is unafraid of falling again (see last pic).

[ctuna]

After the battery reset?

[Pittsburger]

Dash errors were weird I got a 4x4 error and clock 0. So I updated the time. When I started reversing about a minute after, the error messages cleared.

By the way, battery disconnect is so worth it. You won't feel much improvement without the disconnect.

I think the main improvement is at low speeds (when forced air flow is minimal).

[ctuna]

It just wouldn't be as quick to change.

[1QuikWS6]

Dash errors were weird I got a 4x4 error and clock 0. So I updated the time. When I started reversing about a minute after, the error messages cleared.

DSC/DTC error messages are normal after the battery has been disconnected. As you already saw, after a short drive, the error goes away by itself. No harm no foul...

[AndreyT]

Originally Posted by braveplayer3160

Slow down cowboy! By your terminology I take it you have not wrenched on cars that long. If that is the case the key is patients. Lots and lots of patients.

In other words, drive to the nearest hospital.