H F

I've done that many times and never threw a seat belt error .. I just think it's apparent that they installed the battery and you got the fault right after . 1 + 1 = 2 here .. To me it's not a coincidence .. Because they had to disconnect the positive cable and last one to touch it .. Maybe I'm wrong here ,, but it sure looks that way . Get the codes and you'll know for sure . Try and reset the error and hopefully it will clear ..

Gangplank

Starting to think the IBS is the cause of my gremlins & now this too.

Thoughts?

H F

. A failing IBS can drain the battery and can cause a no crank issue ,, even if the battery is charged . If the no start issue continues after ensuring battery and alternator are good ., it would be the next suspect .. Did u have the alternator checked after the installation of the new battery ? You have to rule these two out first .. Also the BST connects to the positive and IBS connects to the negative terminals , and are two separate cables with different duties ..

Gangplank

Haven't had the crank-no-crank issue since Tuesday mid-day. So that went away before the battery was replaced. The other weirdness was Tuesday afternoon & night. All was normal Wed. & Thurs. The Battery was 3.5 yrs old so I decided to just go ahead and replace it.

Btw the message I'm getting now is "Fault in passenger-restraint system affecting airbag, belt tensioner or belt force limiter."

I'll have the shop read the codes on Monday or Tuesday.

I'm going to get BMWhat & order a wifi dongle. Don't have it now so not much I can do right now.

Gangplank

What different duties do they each do?

So my culprit for the Pass Restraint Failure might be the BST on the negative cable?

H F

The IBS monitors the battery's state of charge . Sends voltage information to the DME . If the IBS sends correct starting voltage information , the DME enables the wake up signal to the IBS and the DME activates the ignition ,injectors and starter.

IF the IBS sends a low wake up signal ( minimum starting voltage ) , the DME will not allow the IBS to wake up the car and stays in sleep mode , not activating the starting systems ..

The BST is the battery safety terminal ,, which is a disconnect feature on the positive battery terminal .. Which disconnects the power cable to the starter ., and has a chip that works in conjunction with the air bag system .. So if there is any movement inside the disconnect mechanizum it will trip the sensor then an air bag warning ...

There are several elements that will trip the same error on the idrive .. getting the code will tell the story and cause of the error ..

Gangplank

Got it!! Thanks for the info & explanation!!

dh1

Just curious if you had the battery installed at the dealer, did they "register" the new battery?

My 545 is experiencing the same no-crank deal right now. I accused my wife of not knowing how to start my car because she turned the key 4 times and it didn't crank until the 4th time. I drove it the next day, no problems. Drove it for the last 2 weeks, no problems. Yesterday, it did the no-crank thing to me after picking my son up from school.

Dealer tells me over the phone that they are confident a new battery is the answer. Theirs is $440 installed, with the registration done. $80 just to register the battery if I buy my own and install it myself. The shop manager said that if you don't register it, you can expect your car to continue to behave as if there are electrical issues, because it 'remembers' the condition of the failed battery, despite having a new battery installed.

Anyway....did you get your battery registered?

Gangplank

Had mine installed by an Indy and he did register it w/ the software he has.

twh

The car DOES NOT remember the condition of the "failed battery". That is, if the battery is failed, the car hasn't done anything to remember that specifically. The car DOES have a different charging profile for new batteries that is changes as the battery ages (i.e. time goes by after the battery registration). Go online and find a $40 off coupon from Advance Auto Parts and get their battery - should cost you about $150. Depending on your model year, it will be a traditional flooded lead acid battery or an AGM battery. Get the same kind as in the car now - flooded or AGM. Buy a K+DCAN cable with software and register it yourself. You can use the free version of BMW Logger with the cable - this is super easy to use. Download the right version that matches your DME (car computer). I replaced my 2006 E60 battery and my wife's 2009 X5 battery recently and didn't register them for months without issue.