Battery/Alternator weird issues?
 

Hey guys me again! I swear every other month I got a weird issue with this car or something going bad on it...

Anyway so recently (past month or so) I was having massive battery drain issues from a faulty upper trunk hatch latch. Since then I have fixed it by just straight up unplugging it since at the moment I couldn't swing the $300+ dollars for the repair and it's not totally essential the car drives with with no trunk access.

Oddly enough once that got fixed I still was having weird battery issues. Car showing low battery or completely not starting at times, once I even had the car just completely die on me while driving. So I assumed it was the alternator right? Well I turn the car on and test that with a voltage meter and it's showing 14v output. So then I was like alright maybe it's the battery doing weird things, test the battery it shows 12v with the car off and took it to get tested and it showed it as all good.

So now I'm stumped and it's getting weirder and weirder. I haven't had my car die on me completely or anything but if it sits for over a die without starting the car battery is completely drained or dead won't start. Even if I do drive it every day, I ALWAYS get the red battery light on the dash which sometimes eventually goes away and other times my car completely goes into limp mode, 4x4 warning flashes on and off and on and off break warning on and off until it weirdly stabilizes and I get wherever I need in transmission failsafe mode.

Sooo yeah I have no idea what to do besides just buy a new alternator and test it? Any other ideas guys? Also per usual sorry for crap formatting if it is typing on my phone.

Check the IVM.

Thanks for the reply, any idea where the IVM is on a 2006 X5 4.8is? And or how to check it?

You can buy one at Amazon. https://www.amazon.com/BMW-Integrate.../dp/B00AG39RRS

Bentley Manual show the location. I'm not aware of what test you can perform other than voltage and ohm.

Okay cool thank you! This has been sucha headache in just not knowing what the hell was going on haha. I guess from now of when in doubt if a weird issue is going on see if there's a module that controls it went bad. 🙄😂

I'll probably just bite the bullet and buy the module as it really has to be since the alternator checks out and so does the battery. I'll buy it either today or tomorrow and report back!

Found a video on replacing the IVM, it's for a 6 series BMW, but since you have a later 4.8is it should be the same. Most likely it is in the electrical box on the passenger side of the car.

https://www.youtube.com/watch?v=L8akXREk80w

Sorry for the late reply had to work last night just got up to check the thread this morning. Thank you so much for the video and your help! I'll call around and see who has it in stock near me, if I have to get it directly from BMW there is a dealer not far from me hopefully they have it. When I get it I'll install it and be sure to let you know how it all works out. Thanks again I was completely stumped lol before this thread haha!

You are welcome.

Coming back later to post the results will help other owners in the future with the same problem.

IVM Replacement / Troubleshooting - Bimmerfest - BMW Forums

I just did this repair to my 2006 4.8is . easy repair and it really got my engine running tight, As far as Your battery after You replace the IVM or ISM , it should be no less then 12.7v[to run excellent] cold. the alternator sounds good, mine runs at 14.3 ............I found out that You really have to drive the car on a regular bases to keep the battery charged , or buy a battery charger and keep it charged , these cars are very electrically sensitive .The ISM[BMW calls it ] or IVM is not bad $145 out the door and as You can see on this link that it controls a lot of the engine ,fuel system.
Good luck , I think You will be happy with the results.:thumbup:

Welp I couldnt find anyone who had them in stock for pickup so I placed a order for one on ECSTuning should be here Wednesday or Thursday and will install it then.

Just another note for the story if it helps others. Yesterday I drove the car all day fine no issues not even a battery symbol on the dash besides one or two times. Go to start the car this morning? Deader than a door nail, it barely started and eventually stalled out and wouldn't start again. I guess until I get that part I will have to just keep my X5 on a charger.

@electricalserv x5: I do drive my X5 daily. Only times I don't is once and a while when I have off school and work on the same day I usually relax and get stuff done at home so it sits undriven for a day. But yeah even though my battery "Checked" out fine according to Sams Club, where I bought it, they also showed that it only had 730 out of the 900 cold cranking amps it should have and when I tested the battery myself it kinda fluctuated between 11.3V and 12.3V so after I replace this I will definitely go back and try and have them give me a new battery before winter. After that its time to finish changing suspension on the drivers side, already finished the passengers, and replace the break pads before winter and she "SHOULD" be all good to go hopefully!