[sdnmedia22]

Hi , I have a 2017 540i with lane assist, steering assist and the radar at the front of my car. The adaptive cruise control works well so I know that there are no issues with radar at the bottom under the grill. However, when driving on very well marked roads, it never detects the road lines in order for the steering assist and lane assist to engage. Even on new motorways it doesn’t detect the road markings. It comes on every now and again for around 5-10 seconds and then a yellow steering wheel lights up on my dash and HUD and the assist disengages. I don’t know if anything needs recalibrating or if the steering wheel touch sensor doesn’t work. Has anyone had any experience with this?

[ViA]

what does the bmw dealer say?

[EXHWP]

Did you have the front windscreen replaced? Non compliant screens will cause this sort of problem

[LuvMyE92]

It's probably because the OP is driving on the wrong side of the road, so the system gets confused. "Stay right? Stay left? Where am I?"

LOL, I jest. I've driven a bunch of cars, and the earlier (like in your 2017) lane keeping and autonomous functions really sucked, IMHO, especially when the line paint has faded.

The newer cars are much better, but there's still a limit to what technology can do.

[padresu]

had similar issues with Lane Assistance after windshield replacement. Opted for aftermarket glass - system went haywire - calibration process was done few time, always passed - all good but system would jerk the car left, right, cancel itself, never could find the lines. Replaced glass with BMW - improvement. Had KAFAS camera replaced - under warranty- improvement - Lane Assistance could keep me centered on straight road with well marked lines, better with solid painted lines over interrupted, better at night then day (reflective paint used here). Never less system was of little use since could not cope with any road curve. Lasted this way few months or so.
Now, had to replace car battery - WOW ! immediately next day system works flawlessly - straight road, curve left and right, in city, on highway - higher speeds. perfect! Nothing else was done but car battery placed, registered and now Lane Assistance is perfect! Does not need well painted lines in city, follows car ahead of me.

[pault1980]

If (when it 's actually engaged) the yellow steering warning is coming on and you touching the steering wheel isn't resetting it back to green then you have an issue with what I'd expect is the sensor in the steering wheel that tells it you have your hand on the wheel.
I'm in Australia and mine works "ok" - if it has a car to follow it'll use that even without road markings but with road markings is more accurate. Anything over crawling speed and it'll ask me to touch the steering wheel every ten seconds or so. At crawl speeds its brilliant if there isnt stops - I was in slow moving traffic the other week for about half an hour and it would crawl along without asking for intervention for up to about 5 minutes. It's not great however - The hands free lane change is deactivated in Australia which sucks and it seems to hug the left side of the lane sometimes (we drive on the left down under) which can get a bit close to adjacent cars or trucks though I suppose that's better than the other extreme of oncoming traffic.

[Volasko]

Are the two lines that come up surrounding the steering wheel icon yellow/green (can’t remember exactly) or grey when you’re having issues? If it’s grey the system isn’t reading the lines correctly and the assist is disabled. It took me a while to realize this, after a few sketchy moments where I put too much trust into the systems.

[sdnmedia22]

Originally Posted by Volasko

Are the two lines that come up surrounding the steering wheel icon yellow/green (can’t remember exactly) or grey when you’re having issues? If it’s grey the system isn’t reading the lines correctly and the assist is disabled. It took me a while to realize this, after a few sketchy moments where I put too much trust into the systems.

The system detects the lanes and the lines on the dash turn green, sometimes it works for around 30 seconds to a minute. But 90% of the times the road lines get detected and around 5/10 seconds after a yellow steering wheel appears and the lines aren’t detected anymore. I’m thinking that the touch sensors are faulty but I’m not sure how to test it as there are no fault codes when scanning.

[arkhi]

Originally Posted by sdnmedia22

The system detects the lanes and the lines on the dash turn green, sometimes it works for around 30 seconds to a minute. But 90% of the times the road lines get detected and around 5/10 seconds after a yellow steering wheel appears and the lines aren’t detected anymore. I’m thinking that the touch sensors are faulty but I’m not sure how to test it as there are no fault codes when scanning.

That's probably because it disengaged. When the system is disengaged, the lines are gray (speaking from an LCI G30 btw).

I too suspect that your wheel touch sensor is broken. However, before going around replacing it, I'd rather open up the connections and reseat them just to be sure first. Go to BMW Techinfo and look around the diagrams to see how you can go about doing this, as well as other docs that might help you diagnose this.

[RoyB]

My M340 disengages lane assist when there's a break in the lines on one side. ie: intersections or lane exits. It does engage when it sees the lines again.

If the wheel touch sensors are broken I would expect it to tell you to put your hands on the wheel before disengaging. It does on mine anyways.

[lewvndowski]

Originally Posted by sdnmedia22

The system detects the lanes and the lines on the dash turn green, sometimes it works for around 30 seconds to a minute. But 90% of the times the road lines get detected and around 5/10 seconds after a yellow steering wheel appears and the lines aren’t detected anymore. I’m thinking that the touch sensors are faulty but I’m not sure how to test it as there are no fault codes when scanning.

Hi, did you solve this problem? I have the same thing as you. The assistant recognizes the lanes on the road for about 30 seconds and even though I hold the steering wheel, the yellow steering wheel symbol appears on the HUD (without the animation with hands, which is displayed when no hands are detected on the steering wheel), the system stops working for about 20 seconds, then it finds markings again and so on for 500 km.

[AP]

Have a read of this thread as I think it has your answer ( hint reset)

https://g30.bimmerpost.com/forums/sh....php?t=1947268

[lewvndowski]

Originally Posted by AP

Have a read of this thread as I think it has your answer ( hint reset)

https://g30.bimmerpost.com/forums/sh....php?t=1947268

So i did this trick with battery and.... my lane assist works like a new. WTF

[AP]

Good news and saves a potential costly visit to dealer. I wonder if a dealer would diagnose it this way aswell?

[lewvndowski]

I think they know it can be "fixed" this way. But that's not their job I worked at Audi in Germany and I know how this system works, it's the same in every brand.