Adaptive cruise windscreen

[TedStriker]

Hi,
I'm going to be adding adaptive cruise to my 2018 94ah rex. I've read that you need to swap the windscreen as the non adaptive one doesn't have the mount for the camera. I'm just wondering if it's absolutely essential? No way round it? The rest of the parts are quite reasonable but a windscreen is WAY expensive!
Any and all thoughts/suggestions welcome....
Ted

 

[mojo]

I'm just wondering if it's absolutely essential?

What do you mean by "it"? The camera? Something to mount the camera in? Adaptive cruise definitely requires the camera. I believe that the mounting area also includes a heating element built into the screen so that any misting on the area of glass in front of the camera can be cleared (by turning on the HRW).

One further question: have you driven an i3 with adaptive cruise? My car has it and, having used it regularly for over a year now, I would not be jumping through any hoops to add it to a car that didn't have it! I personally don't think it works at all well.

 

[alohart]

I suspect that the wiring for the camera doesn't exist in an i3 without this camera. Many i3 features are controlled by electronic modules that pass data over several data busses. Trying to retrofit the camera and its connections to power, controllers, and data busses seems very difficult. Even after making all of the connections, the module would almost certainly need to be programmed to recognize the camera. It might cost less to replace your i3 with one that includes the Tech Package.

 

[alohart]

One further question: have you driven an i3 with adaptive cruise? My car has it and, having used it regularly for over a year now, I would not be jumping through any hoops to add it to a car that didn't have it! I personally don't think it works at all well.

If one commutes during normal business hours on routes that face roughly east or west, sun blinding might make ACC disconnect repeatedly. Heavy precipitation could also cause disconnects. However, many of us don't drive east or west early or late in the day, so sun blinding isn't a significant problem. Heavy precipitation isn't common where I live. ACC does occasionally disconnect when I drive under a dark underpass brightly illuminated by sunshine, but this situation isn't common where I drive. I drive everywhere under the control of ACC. We're on our 3rd i3 and eliminated i3's without ACC from purchase consideration.

 

[mojo]

There are a couple of other things that seem to give my car problems: One is sideways sunlight on any road with trees along it. The "striped" effect of the tree shadows across the road causes it to repeatedly speed up and slow down - not by much, but it causes a not-so-pleasant surging effect. And it does not seem to be able to compensate for the size of large heavy goods vehicles - so it seems to sit a significant distance back from large vehicles.

Neither of these cause it to drop out, so they are just minor irritations more than anything else - but I'm pretty sure a radar-based system would not suffer from any of these problems.

 

[Neil]

If one commutes during normal business hours on routes that face roughly east or west, sun blinding might make ACC disconnect repeatedly.

I endured this phenomenon for over 5 years commuting East in the morning and West in the evening. ACC was unusable during certain times of the year. Also I quickly found out that it apparently had a hard time seeing white box trucks in front of me.

 

[TedStriker]

Sorry, didn't mean this thread to turn inot a pros and cons of adaptive cruise!

I've installed adaptive cruise in my F32 435d which is a way bigger job as it needs ABS sensors, ABS pump, body control ECU, radar etc so not afriad of this one, it's just the cost of a new windscreen that's getting in my way right now.

So back to the original question - what's so different about the adaptive cruise windscreen? I'm guessing the glass itself is the same, just with different bits stuck to it for mounting etc, and different areas blanked off/open up for the camera to see out of. Something that could be modified?

Any experience anyone?

Thanks!

 

[mojo]

If you haven't already, it would be worth reading the "Driver Assistance Systems" section of the product I01 technical manuals, as that section describes the system and shows the layout of the main parts on the windscreen.

It seems likely that the "KAFAS camera heating" will involve wires brought up to the edge of the screen - but it does not deal with that in any detail at all. I ~think~ the masked area of the screen is deeper than cars without KAFAS - it includes both an almost triangular clear area for the camera and a circular clear area underneath for the Rain‐light‐solar-condensation sensor.

If you take a look at a front photo of a vehicle of both types, I'm pretty sure that the extra depth of the masked area will be obvious.

 

[JamesInLondon]

My car came fitted with ACC and TJA, but if I try to use TJA in town, I get the message "TJA only for motorway use" and on the one occasion I tried to use it on a motorway I received the message "TJA only operates up to 35mph".
Anyone in the UK managed to actually use TJA?

 

[mojo]

Is your car pre- or post-LCI? I was under the impression that no post-LCI cars had TJA in the UK. My 2021 car has Driver Assistance Plus and was built just before the Covid parts shortage - it does not have TJA.

 

[JamesInLondon]

Is your car pre- or post-LCI? I was under the impression that no post-LCI cars had TJA in the UK. My 2021 car has Driver Assistance Plus and was built just before the Covid parts shortage - it does not have TJA.

My car is a 2017 66 plate.

 

[mojo]

Is your car pre- or post-LCI?

 

[JamesInLondon]

Is your car pre- or post-LCI?

I have no idea what that means

 

[mojo]

LCI is the upgrade that BMW made in 2017 (I believe it's the initials of a German language term, but I've never looked in any detail at what it stands for).

Knowing that your car was first registered in 2017 doesn't answer the question of which side of the upgrade your car is on - it could be either.

You can recognise post-LCI cars because they look different than pre-LCI - the obvious difference being that the circular main (high) beam lamps in the front bumper where removed, and main beam lighting was moved into the main headlight itself.

 

[JamesInLondon]

Mine has the round lights below the headlights

 

[mojo]

Which of course makes it pre-LCI. I've yet to hear of a post-LCI European spec car with TJA. Perhaps it was a cost control change, but that seem unlikely, as most of the parts will still be there on a car with ACC. From what I can tell, only the steering wheel (including one module) is different.

 

[JamesInLondon]

But, does anyone know the answer to my question?

"My car came fitted with ACC and TJA, but if I try to use TJA in town, I get the message "TJA only for motorway use" and on the one occasion I tried to use it on a motorway I received the message "TJA only operates up to 35mph".
Anyone in the UK managed to actually use TJA?"

 

[mojo]

I thought there was a thread on this only a few days ago? Perhaps it was on another forum, but the suggestion there was that TJA recognises the type of road (possibly from the number of lanes?) and only permits you to use it in the circumstances that you describe.

Have you actually tried to use it in the circumstances that the system describes - i.e. on a motorway, at or below 35 MPH?