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Discussion Starter #1
My factory backup camera in my 2016 Metis locked up on me this morning. By locking up I mean the moving picture became static. I was backing out of my garage and about half way out when the image froze. I put the van into park, then into reverse again, and the image was still froze. I pulled forward a little, then back into reverse and it was still froze. I parked the van in my driveway and a few hours later I started it up and into reverse again but the backup camera was working again.

Has anybody else had this happen?

And let me say this. If this subject has come up before, well I’m sorry, I don’t read every thread posted here.
 

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It's annoying, (haven't had it happen) but I'm not sure why it would be dangerous. Not saying that it should happen, that it's excusable, or that Mercedes shouldn't fix it.

But how precisely is it's failure dangerous?
 

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It's annoying, (haven't had it happen) but I'm not sure why it would be dangerous. Not saying that it should happen, that it's excusable, or that Mercedes shouldn't fix it.

But how precisely is it's failure dangerous?
?

A rear view camera that quietly stops updating can provide a false negative. Potentially a very convincing false negative. The driver could view the screen and see a clear path behind when something might have moved into the space.

These systems have to fail safe, i.e. have the screen go black. Displaying a stale image is the opposite of failing safe.

The NHTSA will forward complaints to Mercedes. If a pattern emerges they may demand that it get fixed.

https://www-odi.nhtsa.dot.gov/VehicleComplaint/
 

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A fail safe would have to be able to detect the image wasn't updating, which is quite difficult to do when the image can be extremely static even when it is working.

Further, a back up camera is an aid. I use the thing for precise location of my car when backing up (useful when, for instance, it is longer than many parking spaces, and therefore I want to get as close to the end of the spot as I can, or leaving myself just enough space to have the tailgate clear the car behind me).

If you are backing your car up into potentially fluid situations, you should be sweep checking the screen and all of the mirrors (I still reccomend small sphere mirrors) as you've do it. Even when it is working properly, it can't detect things out of its field of view, and you should only trust it as an advisory measure.

You should ALWAYS assume it is possible that any and all safety features, like lane keep assist, (or even ABS) might cease working without the car diagnosing it. Not saying it does, but you should still operate under the assumption that you need to be able devote your full powers of reaction and observation to driving. Just because you have a safety net under your tight rope does not mean you shouldn't worry about falling off it.
 

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Discussion Starter #6
It's annoying, (haven't had it happen) but I'm not sure why it would be dangerous. Not saying that it should happen, that it's excusable, or that Mercedes shouldn't fix it.

But how precisely is it's failure dangerous?

Really? You don't see how this failure is dangerous? I'm guessing you don't have a Metris Cargo with a cargo partition. The camera is the only way to see what's directly in back of you, and if the "moving picture" freezes, you can't see if you are going to hit anything.
 

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A fail safe would have to be able to detect the image wasn't updating, which is quite difficult to do when the image can be extremely static even when it is working.
Detecting a perfectly static image is not difficult. Regardless, that's not how it would be implemented.

A failsafe would work by expiring the display if the hardware frame counter isn't incrementing, or via a watchdog that's reset by the vertical blank - something along those lines. The details, and therefore the guilty party, depend on where the frame buffer is implemented.

For what it's worth, I worked on SOC imagers for automotive backup cameras. I can tell you that we took this stuff seriously. A frozen image is recognized as unsafe and is considered to be a Big Deal.
Further, a back up camera is an aid.
I'm sorry but this is a cop-out.

We are not merely talking about failure of a nice-to-have driver's aid that everyone should be prepared to live without. A frozen image is much worse. It is perfect misinformation.
 

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Detecting a perfectly static image is not difficult. Regardless, that's not how it would be implemented.

A failsafe would work by expiring the display if the hardware frame counter isn't incrementing, or via a watchdog that's reset by the vertical blank - something along those lines. The details, and therefore the guilty party, depend on where the frame buffer is implemented.

For what it's worth, I worked on SOC imagers for automotive backup cameras. I can tell you that we took this stuff seriously. A frozen image is recognized as unsafe and is considered to be a Big Deal.I'm sorry but this is a cop-out.

We are not merely talking about failure of a nice-to-have driver's aid that everyone should be prepared to live without. A frozen image is much worse. It is perfect misinformation.
I think what -greenmanedlion is saying is that we are all too dependent on electronic safety items and we should still keep in mind that these might fail, however, since these items are put in to safeguard the driver, but more importantly, anyone around the vihicle, these modern so called "luxury safety items" are now in fact a need to have safety item, that should work, especially for those now who need this as the ONLY means of seeing in the back, like a cargo van without windows (or even with). If any car manufacturer puts it in as a safety measure, then the company should ensure it to work at all times, just as it treats seat belts, breakes and other important components of a vihicle.
 

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I think what -greenmanedlion is saying is that we are all too dependent on electronic safety items and we should still keep in mind that these might fail, however, since these items are put in to safeguard the driver, but more importantly, anyone around the vihicle, these modern so called "luxury safety items" are now in fact a need to have safety item, that should work, especially for those now who need this as the ONLY means of seeing in the back, like a cargo van without windows (or even with). If any car manufacturer puts it in as a safety measure, then the company should ensure it to work at all times, just as it treats seat belts, breakes and other important components of a vihicle.
It's not the failure per se of the backup camera that I regard as dangerous. It's this particular mode of failure. If the screen went blank, or displayed a test pattern, or a dim or obviously distorted image, I would agree.

A frozen image is different. The driver is presented a coherent picture of the actual surroundings, except it has been shifted in time. It actually takes a lot of electronic hardware working exactly wrong to pull off this hoax.
 

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It's not the failure per se of the backup camera that I regard as dangerous. It's this particular mode of failure. If the screen went blank, or displayed a test pattern, or a dim or obviously distorted image, I would agree.

A frozen image is different. The driver is presented a coherent picture of the actual surroundings, except it has been shifted in time. It actually takes a lot of electronic hardware working exactly wrong to pull off this hoax.
I completely agree with you on that. I am just thinking as others in so many words indicated, what did we do before all this technology? At any rate it is a dangerous condition and a clearer indication of failure on the hard/software is needed from the manufacturer.
 

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The issue with fail safe indicators for everything is we start to trust the indicator- that is, without an indication something is wrong, we therefore believe this to in fact be an indication nothing is wrong.

And the fact of the matter is, sometimes the indicator is broken. For instance, on my 124 a tail light burnt out. However, so did the light out indicator bulb on the instrument panel. Therefore, I was not aware that a bulb was out- until I did my weekly light test walk around.

Cars are dangerous devices, inherently. A metris is 5000 lbs of momentum adhered to the road by four patches of rubber several inches square. It is aided in that by some sophisticated electronics that can fail. And that is a good thing, because when they work they save lives. But when we take them for granted and they fail, they take lives, too.
 

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This thread was started to discuss backup camera malfunction got strayed to fail safe and never rely on indicators...
 
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