[Gemini_70]

At the outset, I note this is my first post on a BMW forum ever! Please be kind. I was reading an old thread which had links to wiring diagrams for the tailgate area in the E91. All the diagrams in the old threads have been taken down because BMW has demanded it. I think BMW is showing the heights of corporate greed, and I agree with the people who took down their diagram links that BMW is violating the Right to Repair. And that demanding people not share their knowledge and pics of diagrams is unlawful and unjust. Especially in light of the fact that their dealerships clearly don't want to deal with these issues. One I had a smug dealership guy tell me that their dealership would never sale a car older than 5 years old.

My last seven of my vin are A542888.
I have a similar issue. Here is my problem in detail. I just bought this 2011 BMW E91 328ix.
First issue is that the Rear tailgate window opens randomly. I have noted a couple specific times it happens. It happens more frequently when it rains. It happens the most when I insert the key fob to start the car especially in the rain.
However, on two occasions, it also has opened as I passed with in about 4 feet of the rear passenger door. I note the car doesn't have comfort access, and I wasn't engaging the central locking system with the fob at the time.
I have had the car for about 20 days. There was about a week when every time I entered the car I received a low battery message in the dash check. During that time the car was dead in the morning on about 5 different occasions.
I noticed that the rear tailgate window may have popped open and thus the cargo area interior lights could have drained the battery. However this was not every time. So i definitely have a parasitic battery drain but not all the time.

At one point I had trouble jump starting the car. I just wouldn't take the charge. I was afraid the battery was completely dead, but It may also have been crappy cables. Thus I removed the battery and place it on a trickle charger overnight and took it to advance auto. They tested the battery said it was in fact good and was actually overcharged.
I replaced the battery and the car started right up.

My next attempt to sus out the issue led me to installing a new microswitch. I note that the old switch worked most of the time, but I saw the reports that its seal fails allowing water to short the circuit. The new switch failed to open the tailgate window during use, and the window continued to open randomly. I note that when I was taking the old microswitch off I broke its connecting wires. So I replaced the new microswitch with the now broken one with no wires, thinking that if it no longer popped open, I'd live with it and call it a day. I also figured that if it opened randomly with a switch with no wires I could rule out the switch as the cause of the problem.

However I now believe that may not be entirely accurate as I've come to learn that the is a constant ground that is supposed to go to this switch and the fact that its being left open may actually also still be a cause for it to open. Honestly I'm not sure. I have the new switch but I haven't put it back on. Instead I started down the rabbit hole of the the issue if not the switch is most likely the wiring looms in the tailgate.

I have taken no further action besides trying to read about the issue on these forums and watching about 7 or 8 Youtube videos of guys attempting to to fix this issue by means going from completely cutting all the wiring looms and re wiring them to others who tried to only cut the rubber protective grommets and inspect the wires for breaks and cracks. I've come to think that the wires affecting the rear window of tailgate are on the left side of the tailgate.
I know enough to know that I don't fell comfortable just cutting shit and trying to repair a cluster of wires that I have no clue what they do. I know at the moment I have a bothersome rear window that opens randomly and sometime causes a battery drain. However I've seen the videos of guys who keys won't work due to wires to the diversity antenna to others who's tailgate don't function at all or that have lights in the tailgate are fail.

Thus, I am trying to get as much details as I can. Armed with this knowledge, I may then turn to help of someone who installs stereos or I have a lead of a guy who "specializes" in these kind of issue. But honestly I'm not sure how much I trust either of those options. So I guess my goal is to learn as much as I can and then decide it I can do this myself or seek help. At least I figure If I know what needs to be done I can save whom ever I seek out to help the time of learning what exactly is wrong. I am confident of this, I will spend more time and effort in defining the problem than most people who I can turn to for help. I have been thinking out it this way I can have the knowledge to supervise what needs to be done and just someone proficient with stripping wires and soldering splicing etc.
In the last comment, the author wrote "it seems like either a problem with either the switch in the rear window lock M96a, or the wiring somewhere in between X13059 and X14271."
Mine seems to be the same? But I admit I have no idea as to what X13059 and X14271 are as the diagrams have been taken down.
I also tried to focus on if the main tailgate lock actuator could be the cause of the rear tailgate window opening. I've read vague things that call the lock actuator a solenoid which in fact controls the the release of the window. Basically leading me to think that the microswitch is a trigger that sends a signal to the lock actuator which is really not so much as a positive electrical charge as it is a break in the ground, which in turn opens the circuit releasing the window. Which also explains how a partially broken or uninsulated ground wire moving and making contact with the chassis breaks the circuit and releases the window. But I really want to know exactly how this works what actually releases the window the micro switch or the lock actuator.
Lastly, as I just bought the car I not sure if if these two other issues are related but I I will note them just in case. The inside of the car is in immaculate condition it has the fin cut aluminum trim and there's not a scratch on it, but the Idrive controller for the CIC system is not working. It doesn't have power as i doesn't light up or move the curser on the display ever. I have not pulled the controller out to inspect it. I really thought it was an unrelated issue, and that someone probably spilled something on it. The cic system works with voice control otherwise. The final thing the car dealer I bought it from told me he took it in on trade in March and he put a new starter in it. There is a receipt in the glove box. He didn't say why he had to replace the starter and I have seen no issues with the starter. Oh and I checked all the fuses in the glove box related with central locking system, CIC, and a couple of other things. I apologize for the length of this post and thank you in advance for any advice and information including the wiring diagrams I need.

[StradaRedlands]

Gemini_70Being kind, but you may want to edit that wall of text down some LOL
Reminder: There is no good writing, only good editing!
My only suggestion for the hatch is you do not need to cut anything to check the wiring. just pop off the spoiler (five bolts, funky one in the middle IIRC) and then you can see the rubber boots. Just pry one off and gently pull the wires. If one or more separate, there's your problem! You are stuck with repairing at that point, but not hard to DIY or at least you could take to an auto-electric specialist near you and they can see what to repair.

Good luck, and welcome aboard!

[e91Owner]

I could only get through the first paragraph of your message. What’s that phrase? Brevity is the soul of wit? Or you can’t catch a minnow with a steak? Something like that.

In any case, try unplugging the switch itself and leaving it that way for a while. If it stops opening randomly with the switch unplugged, you’ve isolated it to around the switch in either the connector or the switch itself (don’t go cheap on the switch, get an OE one). If it’s still opening after unplugging it, the circuit is grounding elsewhere and then, you have all of the usual suspects.