[Chick Webb]

The Lane Assist on my wife's '17 540i used to be good enough that it prompted me to buy my '19 X5 (and subsequently a '22 X6) with similar capability. No longer. It's now degraded to the point it's unusable. It takes forever to find the lane and when the thing does lock on, nearly anything will cause it to shut off. The gentlest curve, a bump in the road, etc. Not happy.

So, two questions:

1. I've seen some other threads that suggest the windshield cameras may need calibration or even replacement. Is that the most likely cause or are there other things I should be asking the dealer about?
2. I swear on a stack of bibles that it used to signal (chime) when the lane assist turned off, in addition to turning the steering wheel icon gray. Is that true or is my mind playing tricks on me?

Any help would be appreciated. The car's at the dealer right now and being diagnosed. I don't want to let them give it back to me until this is resolved (the car's got an extended warranty) so I need to be able to respond if they say it's OK as is, or that they can't diagnose it.

[paquet]

Software update to idrive helped sort the issue out for me.
Hopefully that helps you too.

[AP]

I've just recently experienced similar issues, car is 5 years old and I have used it a lot so used to its limitations
But suddenly it has become unusable
Difficulty locking on to the road markings to engage and suspect same reason why it's erratic when it does engage

My guess is it's a hardware issue as there are no error messages and don't think it's software as nothing has changed so why suddenly change its behaviour?

Just busy at the moment so not had an opportunity to get a dealer to look at. Hoping they can run some dings or a calibration test on it to identify the issue
Out of warranty so probably not cheap.

[AP]

Only chime is when the prompt for haveing your hands on the wheel expires (about 30 seconds)
No chime that I recall when it loses the road markings and the steering wheel icon changes from green to gray.

[AP]

Be interested in the outcome of yours so please post. If you don't mind if they replace the cameras , how much that would be out of warranty

Curious as to how they test or calibrate it, do they have something they place in front of the car to simulate road markings?

[Chick Webb]

Thanks for the responses. I must've been thinking of the behavior of my X5 re: the chime. I read through the manual and, yeah, you only get that when it shuts off because you've taken your hands off the wheel. We did have them do the software updates as the car had never been updated since new; I suspect that may help somewhat. However, I'm of the opinion (like AP) that the problem is hardware, given the dramatic degradation in performance.

Dealer says it's ready, but I'm skeptical. Heading down there today, though, and intend to take the service manager for a ride to check it out.

[Chick Webb]

Update for those interested. I went down to Monterey and test drove the car with the service manager. It was still not right; randomly dropping out, not stable at all, car was wandering back and forth in the lane even when it was steering itself. Service manager and I returned to the dealer and he told the SA that it didn't seem quite right, but they didn't sound inclined to get the repair authorized by the (Lithia == dealer) warranty folks.

At that point I suggested we see if they had a car on their lot with the same feature and do a comparo. Luckily they had a '18 Alpina B7 with lane assist, so off we go again. Difference was night and day and the SM was convinced that something was wrong. So, after returning to the dealer they sent me on my way with the loaner (840i, really nice car, drives like a dream) and started down the warranty repair path for camera replacement. That was a week ago Thursday. Haven't heard anything since, so I presume it took a while to get the part. I suspect I'll be heading down to pick up the car early next week.

Note: Assuming the problem was signal degradation from the cameras, it seems to me there are at least two possible causes. The obvious one is camera failure. But, what if the cameras were fine, but they were being obscured? They do have to "look" through the windshield, after all. What if the inside surface of the windshield that they need to peer through was dirty, or got some sort of a film on it? Or what if it was on the lenses of the cameras themselves? We've all gotten into cars (even that 840i loaner), where the inside of the windshield has been fogged by smoke or outgassing from the interior materials when it sits out in the hot sun. That's a definite possibility, I think.

When I was at the dealer I looked at my wife's car, which has never been garaged since we've owned it (5 years). The part of the windshield that those cameras look through definitely had some filminess to it. The Alpina, on the other hand, which was likely garaged, looked a lot cleaner and clearer. Anyway, that's what got me thinking of this as a possible cause. Since we are getting a warranty replacement we'll probably never know. And I assume the service techs will thoroughly clean the inside of the windshield as part of the R&R, so the new cameras will perform like champs, I'm sure. But if it wasn't under warranty, I think the first thing I'd have done is suggest pulling the unit out and cleaning, then replacing, the existing cameras.

[RonronEG]

Subbed for update.

[ezaircon4jc]

Aren't the camera enclosures "sealed" to the windscreen? How could film get in there?

[Chick Webb]

Originally Posted by ezaircon4jc

Aren't the camera enclosures "sealed" to the windscreen? How could film get in there?

Yeah, that's likely sealed. I'm speculating about the film, but it seems to me that things like the plastics in a car sitting out in the sun every day for years (we live in California, where it is literally sunshine all day every day for months on end) would be susceptible to deterioration that might cause outgassing of small amounts of material. Once airborne, that would attach itself to the glass, either the inside of the windshield or the camera lens or, likely, both. Ultimately, this could degrade the vision of the camera to the point where the lane assist system simply isn't getting a good enough picture of the road ahead to remain in control.

Like I said, speculation. We've got the warranty, so we'll likely never know.
But if I had to fix this on my dime I'd probably start there. The camera assembly is $2k, according to the dealer. While it's probably a little time/effort to tear that assembly out, clean things up, and replace it, that's gonna be a lot cheaper than buying a new part.

[AP]

$2k for the camera assembly, wow that's expensive and what I'm probably looking at to fix mine

[Chick Webb]

SA called yesterday to say that camera has been replaced but car still isn't performing correctly. They're waiting on BMWNA to advise.

[Chick Webb]

We got the car back a couple of days ago and it is fixed. Yay, team!

Unfortunately, other than replacing the camera and recalibrating, which they had already done to no effect, I do not know specifically what else was required to correct the problem. I asked the service writer (who knows us well and is a straight-up guy) and he said that the service manager refused to tell him! So, either the service guys are trying to gain some job security or they screwed up the first time and don't want to admit it, I think.

So, the good news is that it can be fixed. The bad news is that I cannot provide much help on how. Sorry!

[SteveinArizona]

Originally Posted by Chick Webb

We got the car back a couple of days ago and it is fixed. Yay, team!

Unfortunately, other than replacing the camera and recalibrating, which they had already done to no effect, I do not know specifically what else was required to correct the problem. I asked the service writer (who knows us well and is a straight-up guy) and he said that the service manager refused to tell him! So, either the service guys are trying to gain some job security or they screwed up the first time and don't want to admit it, I think.

So, the good news is that it can be fixed. The bad news is that I cannot provide much help on how. Sorry!

You seem to have developed a rapport with the SM. Have you tried telling him how much you appreciate his help in getting the problem fixed but you are wondering...what was the problem and what was the fix? It is amazing, to me, that they would not tell you.

[Chick Webb]

Originally Posted by SteveinArizona

You seem to have developed a rapport with the SM. Have you tried telling him how much you appreciate his help in getting the problem fixed but you are wondering...what was the problem and what was the fix? It is amazing, to me, that they would not tell you.

Oh, yeah, we chatted about it. He even joked that the service manager may have seen my post and doesn't want to be embarrased in public. I doubt I'll find out the details. Happy it's fixed, especially since it only cost me the warranty deductible.