M4 Convertible "Roof Not Latched"

[sdsurfer007]

Hi All,

I am technically new to the forum though I have been trolling as an observer for about 10 years. Prior to this forum existing I was very active on the e46 fanatics forum but work in software and try to stay offline outside of work as much as possible for sanity.

I know this topic has come up a few times in the past but the threads are quite old at this point and solutions listed have not helped so hoping there are others out there that can give some "newish" feedback. I'm providing some context of how the car is used as well as the issue noted in case it helps shed some light.

I have a 2015 M4 Convertible with about 60,000 miles on it with no modifications (I modded 6 other BMWs and all ended up with various issues caused by mods over time so wife didn't allow it on this car :Laughing Out Loud. The car is driven about once every week or two for short fun rides around town and occasionally longer trips up to drive through fun canyons and places like Big Sur, etc (noting because the car sits for sometimes for extended periods and unclear if that could impact things). There are no notable mechanical or electrical issues with the car (other than what I will note below) and the car has never been in an accident. The car has never been tracked or pushed to its limits other than some moderate pulls from stop.

About 2 years ago, I started getting completely random, non-permanent "Roof Not Latched" errors on the dash (of course shortly after 50,000 miles) which would:
a) Not allow the top to operate
b) Not allow backup camera to work

NOTE: The issue primarily comes up when the top is completely closed. However, I have had two occasions when the top was completely open and would not close but then resolved itself allowing to close after some driving. Once time I got it stuck in the middle but a light tap seemed to make the error go away and it finished.

These would come up randomly while driving or sometimes when just starting the car and then randomly go away while driving after some random period of time. I could go a month or so without seeing it and then have it come up 5 times in a single day / drive or last for hours. Most of the time, it is something that would come up for 5 or so minutes and go away. It has gotten more frequent over time.

I haven't been able to find any rhyme or reason to what triggers it. I had suspected misalignment of the top and thought maybe temperature or humidity conditions affected it but I haven't been able to find a connection of that nature. I had also suspected for a while that possible it would happen more often if sitting without use for too long and could be low battery related (the battery has never been replaced though is the long life expensive lithium ion type and has been tested and is "Green"). It SEEMS like when I'm on a hill or under hard acceleration it comes up more often but that is only anecdotal and unclear if that is really the case (this led me to think misalignment initially).

Before taking it in to the shop, I personally checked alignment (as a non-mechanic looking to see if everything LOOKED aligned and tight), tried adjusting alignment of a few of the pin locking mechanisms behind the rear seats (as suggested on other threads) to no avail, and checked virtually every sensor for loose connections. I also checked for water in the rear seat side panels as I heard that could cause electrical issues but appears the mod on the drain was already done by BMW. I got codes read which include (NOTE: Not all of these appear to be related to a malfunction as some are just the general you did something wrong warnings and others could be old codes that weren't previously cleared):

CTM/CVM-Convertible Top Module
805082 - Active engine start - Unclear what this is?
805084 - Driving speed in intermediate setting of retractable hardtop too high - Seems temporary from moving top at a stop light and having to start to crawl before done
805086 - Side window position unknown - Unclear what this one is
805087 - Driving speed too high - Trying to open or close top at too high of a speed on occasion - TEMPORARY AND HAS DIFFERENT DASH WARNING
805088 - Trunk lid open - Trying to open when didn't know lid was open - TEMPORARY AND HAS DIFFERENT DASH WARNING
805089 - Position of retractable hardtop unknown - This seems like the most likely main fault
80508B - Luggage compartment partition not lowered - Trying to open when partition not down - TEMPORARY AND HAS DIFFERENT DASH WARNING
80508F - Timeout on reception of release from FEM - Unclear what his one is
80509B - Lateral acceleration in intermediate setting of retractable hardtop too high - LIKELY TEMPORARY LIKE OTHER SPEED ONES ABOVE

NOTE: I don't know what codes have or have not been cleared and which ones of these are still coming up as BMW did not share this with me. I have also verified that the errors like the trunk partition, trunk lid, high speed, etc. were just from trying to operate the top at times when it wasn't allowed and not the underlying issue.

I finally gave in and brought it in to a local BMW to have it looked at. I provided them SI B54 09 07 Special Roofs Retractable Hardtop Status Request Supplement from BMW (attached) as a test plan.

NOTE: The hardest part of solving this issue is that the problem isn't constant and doesn't just start whenever you want it to. It takes driving the car for a bit for it to come up.

1) They claim they ran the test procedure above and did not notice any issues (not unexpected since the test could only be run when the warning is NOT on)
2) They checked codes and got the same results I did
3) The "re-rigged" the top for alignment which didn't solve the issue.
4) BMW Germany told them to start replacing sensors and they replaced the following parts which did not solve the problem:
61-13-8-353-746 45 CABLE CONNECTOR: 619900
61-13-5-A4F-528 45 SHRINKING HOSE: 619900
54-37-7-148-152 38 HALL SENSOR, REAR MODULE: 549900
61-31-9-171-484 39 HALL SWITCH: 619900
54-37-5-A19-AA5 39 SET OF BASE PLATE WITH BRACK: 541012
54-37-5-A19-AA4 39 SET OF ROOF TRIM STRIPS PRIM: 549900

5) BMW Germany told them to then replace the main convertible top module which they THOUGHT solved the problem and was the final thing they ended up charging me for. It seemed like the error was gone for a few days but then came back up today.
61-35-7-456-364 49 CONVERTIBLE TOP MODULE: 613020

NOTE: I did get the car washed the day after it seemed to be working fine. Unclear if somehow this is water related.

They claimed there was "nothing else to replace" when they installed this module. This is after the car was in the shop for 6 weeks since they had to keep waiting for parts and couldn't prioritize constant testing. I suggested they should inspect the wiring harnesses for any damage / pinching and they claim everything looks fine.

I recall a thread mentioning something about pressing on the rear left soft panel behind the rear left window but it wasn't clear why or what that was doing to help pinpoint anything. I tried this personally and didn't seem to make a difference.

I'm going to take the car back to them at this point but I'm at a loss and they don't seem to really know what they are doing and just keep asking BMW Germany what to try next. Frankly, it seems like BMW really designed this entire system really poorly as any well designed electrical / mechanical system should have a better fault system that pinpoints the actual issue and better ways to fully test these type of problems. It really feels like they are just spitballing and trying things with no real logic to it.

I love the car in every other aspect but I'm totally frustrated as I couldn't even sell the car private party if I wanted to at this point with this type of problem and makes the car feel completely worthless since many times I drive it I get the warning, the annoying gongs, and get angry.

I'm not sure what recourse I can take at this point if they can't solve the problem. I don't know if I can contact BMW in Germany and file a complaint and try to get someone more knowledgable of this system to work on it. The car is out of warranty of course so the repair is opened ended cost.

Any help or tips are greatly appreciated. If any others have experienced this, what was the solution for you?

Thanks!

[RINSE_DETAILING]

Hi mate did you solve this in the end?having the same issue absolutely fine on dry days soon as we get a bit of rain roof not latched pops up so annoying.
I’ve had drain holes made bigger etc just wondering if you could point me in the right direction where I should be looking
Thanks

[sdsurfer007]

I did not and ended up selling the car to the dealership that couldn’t solve the problem. Disappointing as I loved the car but couldn’t stand the issue. Ended up buying an X5 M50i and X3 M40i since I spend most of my time in the mountains these days.

[RINSE_DETAILING]

Appreciate the reply bud, might have to do the same 🤣