[golfboy1971]

I wonder if some kind-hearted sole might be able to give me a bit of assistance please.
I have a BMW 420 (G26) 2022 model and the sunroof has packed up. It was working perfectly fine one day, and as I drove home I closed the sunshade. The following morning the sunshade/sunroof will not open. There's no noise like motor whirring or any clicking.
I've tried holding the roof button for 45 seconds to do a 'recalibration' but nothing happens.

I assumed this could be just a fuse issue, but I have checked fuses F25, F36, F63 (all at the front) and F258, F266 and F268 (in the rear) and they're all fine, but I'm basing this off a fuse diagram for an i4 model as that's all I can find. The link to this page is https://fuseandrelay.com/bmw/i4.html

Does anyone have the front and rear fuse box diagrams/details for the 420 model please? Or any thoughts on what might have gone wrong.

I've got it booked in at the garage this week, but it's a bit of a pain to get there and leave the car for the day, so I'm trying to avoid this if I can, and it's been a hell of a stressful week already.

Many thanks

[G22b58]

You should be able to download the fuse card for your car from this address:
https://fusecard.bmw.com/

[golfboy1971]

Originally Posted by G22b58

You should be able to download the fuse card for your car from this address:
https://fusecard.bmw.com/

Thanks very much for your help on this, this page looks very useful and I'll bookmark this for the future.

As it happens, I've been postponing installing a firmware update because a family member has been in hospital and I didn't want to risk screwing up my car if it went wrong. However, I've now installed the firmware update and amazingly, the sunroof is now working again!

I guess I should have done the car reset with the old 40 seconds press of the volume button! I know for the future.

[cyam]

My screen got stuck open. After a while it just started working. Then next day - stuck and it would not work at all. Got the "initialization" error, but no amount of re-initializing it worked.

I removed the "roof function center" - section with the sunroof button. Behind that you can see the two motors. I used an allen key and wound up the screen. It moved an inch or two with a few turns. I then used the close button and the screen worked flawlessly many times.

Its as though moving the screen manually fixed the issue.

I'll test it out over the next week and see if the issue comes back.

Here are the details on how to remove the roof function center.

[golfboy1971]

Originally Posted by cyam

My screen got stuck open. After a while it just started working. Then next day - stuck and it would not work at all. Got the "initialization" error, but no amount of re-initializing it worked.

I removed the "roof function center" - section with the sunroof button. Behind that you can see the two motors. I used an allen key and wound up the screen. It moved an inch or two with a few turns. I then used the close button and the screen worked flawlessly many times.

Its as though moving the screen manually fixed the issue.

I'll test it out over the next week and see if the issue comes back.

Here are the details on how to remove the roof function center.

Gosh that's really odd. Could it be that it needs a bit of oil/grease to help it in the early stages of movement? I'm glad you fixed it.

[prostcfc]

Originally Posted by golfboy1971

Gosh that's really odd. Could it be that it needs a bit of oil/grease to help it in the early stages of movement? I'm glad you fixed it.

Multiple people, myself included, have fixed this way. Bunch of people have had motors replaced under warranty, and I suspect this would have fixed it for them. I rarely use the sunroof, and now I never am, haha.

[Mrchris]

Originally Posted by cyam

My screen got stuck open. After a while it just started working. Then next day - stuck and it would not work at all. Got the "initialization" error, but no amount of re-initializing it worked.

I removed the "roof function center" - section with the sunroof button. Behind that you can see the two motors. I used an allen key and wound up the screen. It moved an inch or two with a few turns. I then used the close button and the screen worked flawlessly many times.

Its as though moving the screen manually fixed the issue.

I'll test it out over the next week and see if the issue comes back.

Here are the details on how to remove the roof function center.

This worked for me as well today, Thank you!

[golfboy1971]

Originally Posted by cyam

My screen got stuck open. After a while it just started working. Then next day - stuck and it would not work at all. Got the "initialization" error, but no amount of re-initializing it worked.

I removed the "roof function center" - section with the sunroof button. Behind that you can see the two motors. I used an allen key and wound up the screen. It moved an inch or two with a few turns. I then used the close button and the screen worked flawlessly many times.

Its as though moving the screen manually fixed the issue.

I'll test it out over the next week and see if the issue comes back.

Here are the details on how to remove the roof function center.

I might need to have a look at this as my sunshade has failed again. It would not open at all, however, bizarrely, it would open a tiny bit if I activated the sunroof tilt function, but would definitely not slide back fully as normal. Later the same day I tried again and it shifted a little bit, so I kept going back and forth and eventually it just opened fully... so maybe my motor is sticking, or, the runners are dry and causing too much resistance for the motor.

[prostcfc]

One good thing about warranties expiring is we're seeing people actually try to diagnose and solve things on their own, versus going to the dealer and having them parts swap. When I had this issue, the responses I saw from searching here were along the lines of "went to dealer, they replaced the motors". Well of course that works, but is it necessary? Based on my experience and others here, seems like the answer is "no". I found this solution in a G20 Facebook group, but glad to see it circulating more.

[cyam]

It's been several weeks since I did this manual fix, and it's still working flawlessly for me.

Interestingly I am still under warranty, I just couldn't be bothered with whole process and thought I'd just try this first. It worked.

I'm still using my sunroof and will see if it fails in any other way before the warranty expires.

[golfboy1971]

Originally Posted by cyam

It's been several weeks since I did this manual fix, and it's still working flawlessly for me.

Interestingly I am still under warranty, I just couldn't be bothered with whole process and thought I'd just try this first. It worked.

I'm still using my sunroof and will see if it fails in any other way before the warranty expires.

That's good to hear. I'm in the same position, in that going to the dealer, dropping the car off early, taking a taxi home and then trying to get back later in the day, all whilst I'm working is a bind.
I've managed to get the sun visor to move again later in the day, so I kept operating it open, then close, open then close and finally it opened completely... so I'm thinking maybe some grease on the runners might solve the problem.

[golfboy1971]

So to give an update on this, in case it helps someone else; following on from what Cyam said, as I've now managed to open the sunblind again, I've put a bit of PTFE oil on the runners that the sunblind operates on, just in case there was too much resistance and I also had a chat with a BMW technician. As my car was due to go in to the dealer to get this issue looked at, the technician checked my car remotely for errors etc and he noted that my 12v battery was only at 56% charge, and apparently when the charge is low, the car might stop non-essential items functioning, so I'm wondering if my battery was low the car disabled the sunroof/sunblind. Any thoughts on this? Does anyone know how I can check the battery charge % from within the car? (Mine is a G26 model).

[cyam]

Originally Posted by golfboy1971

So to give an update on this, in case it helps someone else; following on from what Cyam said, as I've now managed to open the sunblind again, I've put a bit of PTFE oil on the runners that the sunblind operates on, just in case there was too much resistance and I also had a chat with a BMW technician. As my car was due to go in to the dealer to get this issue looked at, the technician checked my car remotely for errors etc and he noted that my 12v battery was only at 56% charge, and apparently when the charge is low, the car might stop non-essential items functioning, so I'm wondering if my battery was low the car disabled the sunroof/sunblind. Any thoughts on this? Does anyone know how I can check the battery charge % from within the car? (Mine is a G26 model).

Don't know. What I do know is my battery was recently replaced by BMW with a genuine battery. And I have an onboard volt meter and the battery was showing 12v when engine off and 14v when engine running. Fully charged in other words.

I don't think its the battery. I think the blind motor fails prematurely. I think the blind getting stuck is a first sign that the motor is playing up. I am expecting to see it fail in the future.

Others have said its the runners and some sensors along those runners (or something like that) - but I have seen the dealerships fix this issue for others by replacing the motor when the manual winding we have tried no longer works.

Its a wait and see for me, but I still have nearly 2 years warranty left.

[prostcfc]

Originally Posted by golfboy1971

Does anyone know how I can check the battery charge % from within the car? (Mine is a G26 model).

Bimmerlink will give you these numbers.

It makes sense that it binding is an early sign that the motor(s) are going out. But I'm pretty sure I've seen people have the motors replaced more than once under warranty in short succession. Also think I saw someone get a software update to resolve, or maybe some updated initialization via a newer ISTA+ version. Idk...

[golfboy1971]

Originally Posted by prostcfc

Bimmerlink will give you these numbers.

It makes sense that it binding is an early sign that the motor(s) are going out. But I'm pretty sure I've seen people have the motors replaced more than once under warranty in short succession. Also think I saw someone get a software update to resolve, or maybe some updated initialization via a newer ISTA+ version. Idk...

You could well be right. It would be pretty poor for a 2 year old car to be suffering a failure already, but who knows. So far it's been behaving itself, so I hope it carries on (maybe applying some PTFE oil to the runners has helped).
Thanks for the info about Bimmerlink. Quick question, what's the ISTA+ you referred to?

[golfboy1971]

Originally Posted by cyam

Don't know. What I do know is my battery was recently replaced by BMW with a genuine battery. And I have an onboard volt meter and the battery was showing 12v when engine off and 14v when engine running. Fully charged in other words.

I don't think its the battery. I think the blind motor fails prematurely. I think the blind getting stuck is a first sign that the motor is playing up. I am expecting to see it fail in the future.

Others have said its the runners and some sensors along those runners (or something like that) - but I have seen the dealerships fix this issue for others by replacing the motor when the manual winding we have tried no longer works.

Its a wait and see for me, but I still have nearly 2 years warranty left.

It seems a few people have pointed out the motor giving up early. I did wonder if the runners are getting dry and causing undue stress on the motor, or even inside the cable that's pulling the blind back and forth. I've applied some PTFE to the runner area and so far it's been fine (and the motor sounds like it's running a bit faster) so maybe it's part of the issue. I need to have a look at putting some PTFE oil on the sunroof glass runner too, as the motor does sound like it's struggling a slight bit when that's opening.
Thanks for your help. I hope yours keeps running trouble-free now.

[prostcfc]

Originally Posted by golfboy1971

Quick question, what's the ISTA+ you referred to?

ISTA+ is the BMW-developed diagnostic and coding software that's used on our cars. There are versions floating around for end users like us as well.