[Winstar]

so if it's there it's practically in the center of the roof, not under the shark fin...

anyway shouldn't I see some cables coming from there?

anyway next thing is to see in the trunk, then if not there, I'll try to figure out how to loosen the headliner

[Poochie]

Originally Posted by Winstar

so if it's there it's practically in the center of the roof, not under the shark fin...

anyway shouldn't I see some cables coming from there?

anyway next thing is to see in the trunk, then if not there, I'll try to figure out how to loosen the headliner

If you have access to ISTA+, it tells you where your TCU is located..


..

[Winstar]

Ok nothing to do, my TCU is NOT in the trunk...

meanwhile, the error disappeared for a week and reappeared yesterday

[dmaxdmax]

Originally Posted by Winstar

Ok nothing to do, my TCU is NOT in the trunk...

meanwhile, the error disappeared for a week and reappeared yesterday

Maybe they hid it on you so they could get your $300 to replace a $50 battery?

Mine 'was' just forward of the third brake light...perhaps with different option packages they move them around...but the TIS clearly showed only two locations...trunk or hood.

D

[Winstar]

do they really charge $300 even if the problem is only the battery?

[dmaxdmax]

Originally Posted by Winstar

do they really charge $300 even if the problem is only the battery?

I may have been approximating a bit, but to follow the TIS, knowing what to do already, without breaking parts, it's at least an hour's work.

The $50 battery I got online might well be a $120 bat at the dealer.

If your headliner is already opened, maybe they'd cut you a break, though maybe put the third brake light up without the cover to drive to dealer...just coz people are idiots!

Sorry you're having such a difficult time. Like I said, maybe, on yours, because of specific options, they've tucked it somewhere else...but everything I've seen says 'either' trunk or roof. Have you removed the panel from under the trunk cover...I think I had something like that when I looked in my trunk first...

Also, perhaps Euro models are configured differently by themselves. If you didn't remove the c-pillars, maybe they hid it there. Have you tried calling the dealer and asking for help--maybe whimper a little so they'll feel sorry for you? If you haven't bought your battery yet, maybe buy it from them and ask the parts guy...if he likes you, he'll find out.

...anyway...sorry I couldn't help you find it.

[Winstar]

yesterday I removed my 3rd light for - like - the 5th time. Probably I touched something inside the roof with my finger. The position is very uncomfortable. How can I find a good diy guide to remove c pillars and loosen the headliner? Anyway I think it's a work beyond my capabilities. I'll ask them to do that on my next scheduled maintenance (and this will be my first paid one) but I'll say to them, fix it only if it's the battery, I don't want to change the TCU

[dmaxdmax]

Originally Posted by Winstar

yesterday I removed my 3rd light for - like - the 5th time. Probably I touched something inside the roof with my finger. The position is very uncomfortable. How can I find a good diy guide to remove c pillars and loosen the headliner? Anyway I think it's a work beyond my capabilities. I'll ask them to do that on my next scheduled maintenance (and this will be my first paid one) but I'll say to them, fix it only if it's the battery, I don't want to change the TCU

I know the TIS disappeared online...not sure there's a replacement anywhere yet, but I'm sure there will be eventually.

I recall specific instructions about removing the c-pillar...but forget them! I think I pryed out from the inside bottom first, then the top. You'd break clips going the wrong way...not the worst.

Also, there was one screw holding the rear center of the headliner up that I recall having to remove to pull headliner down enough to reach tcu. I thought I could have done it without removing the pillars, but you need to take out one screw.

I have my limits too...at some point give them money and let them deal with it! That said, I think you might be just one screw away.

[GHOSTMAN]

I have the same problem where I have an "Emergency Call Malfunction" with a yellow triangle rendering my BC button useless.

I have looked at basically every forum on this site about this issue and it seems like the TCU battery found in the headliner/trunk is the simplest solution to this.

When I go to check my F30, I pulled down the third brake light housing and looked and could only see the wiring going to the shark fin and the black antenna amplifier box with no white TCU battery housing in sight.

I've also looked under the floor of my trunk and only find a fuze box and another gray metal box with several wires going in and out of it. This gray metal box doesn't have a small door to open with the battery like the F36 in this post.

I'm kind of lost on what to do because I don't want to spend roughly $60-80 on a new battery when I can't even find it in the first place.

If you guys have any advice on what I could do, I would greatly appreciate it.

[TheShadow]

Why this thread has taken on a life of its own is just bizarre.

In the USA, only the F30 LCI variants have a TCB under the roof liner. None of the F32 variants do. Nor do any of the F30 pre-LCI.

[dmaxdmax]

Haha...at least it's not oil!

I guess, like me, people hate seeing a yellow warning triangle...and paying bmw 5x what it'd cost them to do on their own.

Very odd they're not finding this unit like I did...though I had a working TIS at the time.

Now, maybe the best thing to do is buy the battery from the local dealer and beg parts guy nicely to confirm where your tcu is. Maybe they'll have a picture of it they can show you?

[TheShadow]

Better know which battery to buy. They are different for different comboxes/locations

Ask the parts department which you need for your VIN, that will identify where the unit is.

[visionaut]

Here’s the part numbers for the two different batteries.

FWIW, RealOEM shows each battery part # (and their corresponding roof or trunk TCU) is applicable to all models (!). See the attached part application list, for the roof variant battery - the trunk mount variant shows the same application list.

So the reason for confusion might be because the TCU location (separate in the trunk or roof-mounted with the ATM) is based on a cars particular telematics options, and not just year/model…

[ivanes66]

Hi. Where is the block ATM1 in the F31 LCI? I bought both batteries (9297787 and 2447710), changed one under the boot floor, the error did not disappear, I cannot find where to change the second battery under the fin...

[Winstar]

My emergency call continues to switch between working and not working. Now it's more often OK than in error. If it was the battery, it should go worse and worse... And it even looks like colder temperatures help (should be the contrary for a battery) I really don't understand, probably I really have a tcu problem...?

[drinkmorejava]

Replying for posterity here because I know this will become more of an issue as these vehicles age.

I have a 2018 3.40 and the telematics battery just died.

Some of this is just my ponderings and I will update as I complete the repair.

First, to Winstar. Your unit is most certainly in the headliner. Take off the third break light by popping the 5 clips. Then undo the two T25 bolts. Then carefully pull down on the middle of the headliner opening to pop 2 clips. You should then have enough room while pulling the headliner down gently to feel the plastic box. Best to use your cellphone camera to get a good look to locate the tab you stick a screwdriver in to release the battery cover. I actually gave up and sort of pried it open.

As far as the battery goes. Someone else postulated there are normal lithium cells inside, and the answer is basically yes.

I'm currently attempting to replace them with XTAR 14500 lithium cells.(https://www.batteryjunction.com/xtar-14500-800.html). There are some technical tradeoffs here that I will post in the coming weeks. It is certainly possible to replace the existing batteries, but if it's not something you're qualified to investigate yourself, it's unlikely to be worth your time over just buying a new pack for $100.