Severe False Alert Sensor Warnings while in reverse after adding an aftermarket tire/wheel to the existing or an aftermarket spare tire tailgate mount

[JustinB]

Yes that is

Thanks for the article from 2012 proposing what is a relatively common technology today used in front collision warning systems, in the form of radar, lidar, and camera based systems. The trouble is this technology is not implemented in the Jeep JL's camera backup system in the way proposed in this document. There is no DSP in the Jeep.

WaX

I was not stating what's in the article is precisely the same system that's in my Jeep. I shared the article because that's what further enlighten me to 'smart camera systems', or whatever we'd like to call it. Either way the systems work simular, providing camera sensing capabilities (Again, software that can use a camera to sense).
Believe me, when I went thru my testing process and I discovered the camera was sensing objects and alerting to them, that was my ah ha moment.
Seing the article later only further substantiated what I already knew.

I'd give a little thought to all those who are commenting, claiming the same as I with their conclusions.
We shouldn't all be discredited, should we? Is it possible, even slightly possible, that you may be wrong?

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[DWaX]

I was not stating what's in the article is precisely the same system that's in my Jeep. I shared the article because that's what further enlighten me to 'smart camera systems', or whatever we'd like to call it. Either way the systems work simular, providing camera sensing capabilities (Again, software that can use a camera to sense).
Believe me, when I went thru my testing process and I discovered the camera was sensing objects and alerting to them, that was my ah ha moment.
Seing the article later only further substantiated what I already knew.

I'd give a little thought to all those who are commenting, claiming the same as I with their conclusions.
We shouldn't all be discredited, should we? Is it possible, even slightly possible, that you may be wrong?

We'll best wishes to you and your one-off jeep with advanced technology no other current jeep wrangler owns.
The rest of us do not have your magic 'smart camera optical object processing recognition software display processing unit.' we just have to settle for the ParkSense® and ParkAssist® products that are the only FCA technologies in production on the rear end of the jeep wrangler line.

You're very lucky indeed.


WaX

 

[JustinB]

I'm still curious for an explanation for why the nearest rear bumper sensor was picking up the valve stem, and continued to follow as the tire was rotated on the carrier one lug at a time, when the sensors don't have direct line of sight and the camera does?

Exactly!!! This can't be understood if a person's glass is already full.

 

[DWaX]

Here is a fun experiment, open rear window or flap. And have a person inside the rear of the jeep dangle something... anything in front of the camera only, while the vehicle is in reverse. Let us know the outcome.

 

[Headbarcode]

Yes, there are 4 total as you can see, i adjusted the center two.

Great looking Jeep you've got there! I may be a bit biased, though...

We'll best wishes to you and your one-off jeep with advanced technology no other current jeep wrangler owns.
The rest of us do not have your magic 'smart camera optical object processing recognition software display processing unit.' we just have to settle for the ParkSense® and ParkAssist® products that are the only FCA technologies in production on the rear end of the jeep wrangler line.

You're very lucky indeed.


WaX

Who really knows exactly what's going on with those systems and their many intertwinings. JustinB and I are just 2 of many members who've been able to quiet the beep by simply rotating the valve stem towards the top. At the same time, there's been just as many members Jeeps over the last few years that weren't "fixed" that easily. To me personally, a 50/50 chance of it working is plenty enough to keep me suggesting it, because I like starting with the cost free options first.

Cheers, buddy!

 

[DWaX]

There are industry complaints of the radio frequency in tpms sensors interfering with the unshielded bumper backup sensor wires, the same also can occur with the unshielded camera cables, but this only disrupts image integrity momentary.

 

[Bananas]

What an interesting thread. Filled with misinformation... Haha.

The rear camera does not feed into any detection systems and its not much of a smart camera at all. Just a typical LVDS camera, that pumps a basic video signal into a receiver. In this case the dash display. The dash screen overlays lane lines and adds sensor warnings on top if the display sourced from the rear sensors only.


WaX

In the case of JL or JT the lane line overlays are actually done by the camera itself and that already processed signal is sent to the screen over LVDS IF U DONT HAVE THE FRONT CAMERA. If u have the front camera the raw video signals are sent to the Video Processing module from both cameras. That module then does the line overlays and sent the selected camera signal to the screen.

But everything else you said in this post and following ones is totally correct and spot on. Your suggestions on testing are exactly what I'd suggest too.

 

[Bananas]

I think because a product manager from Jeep came in here and said they're not linked might be part of the concern. Lol. In saying that, there are definitely more than one or 2 of us who have seen otherwise. He said he would come back and explain but never came back.
@Bananas hopefully you can lend some corporate knowledge here.

Sorry I got totally tied up that day and the next then forgot and I never seem to get notifications when people tag me.

What DWax described in all his posts is spot on except for the minor thing I described on where the overlays are done. The systems do not interact, I was 99.9% sure (always leave yourself an out lol) and confirmed it.

 

[Dyolfknip74]

Sorry I got totally tied up that day and the next then forgot and I never seem to get notifications when people tag me.

What DWax described in all his posts is spot on except for the minor thing I described on where the overlays are done. The systems do not interact, I was 99.9% sure (always leave yourself an out lol) and confirmed it.

So, the sensors are so sensitive and scanning area so wide that they can pick up a tire valve position? I guess that explains how moving the valve will fix the sensor issues.

 

[DWaX]

If rotating the tire on the carrier eliminates the warning then it must be that the tire tread pattern just happens to be at an angle that bounces back the radar signal.

To test, put tire on where there is a reverse warning, unplug or cover the camera lense, you will still get the warning I'll wager.

Another test, swap spare with another tire with the stem down, odds are it then won't trigger as tread pattern will be different slightly.

 

[JustinB]

If rotating the tire on the carrier eliminates the warning then it must be that the tire tread pattern just happens to be at an angle that bounces back the radar signal.

To test, put tire on where there is a reverse warning, unplug or cover the camera lense, you will still get the warning I'll wager.

Another test, swap spare with another tire with the stem down, odds are it then won't trigger as tread pattern will be different slightly.

Good Morning DWax,

I must Man-Up and state that I tested the camera by hanging a stick over the spare tire from inside the vehicle with a string that was hanging at the end of the stick, a string just long enough to hang over the camera but go no farther. This was not easy. It was I alone attempting this, I'm 6'2" and could benefit by taking some yoga classes. Anyways...

I engaged the parking brake, put the jeep in reverse, crawled to the back (because opening a door made the vehicle autopark), and dangled the string over the camera. I was able to see the string on the Uconnect screen and I did not get an alert. With these results, it substantiates your claim. I am now left with bewilderment. Per my previous tests, back when this post started, all my tests left me believing the camera was impacting/alerting the sensors. With my camera unplugged I was not getting alerts. Keeping the wheel & tire in the same position, I'd plug the camera back in and the alerts would resume. This is all baffling to me. None the less, as a man I must stay true. My latest test tells me you are correct, you added some knowledge to my cup. My apologies.
Hope you have a good Thanksgiving.
~justin

 

[Headbarcode]

Still doesn't explain why only the left sensor was triggered when the stem was on the bottom left. When the tire was rotated by one lug position, only the center sensors alerted. And one more lug position got the same right side only alert.

If it's not the camera causing it, the sensors must be reading through the tire.

Either way you cut it, enough fixes have been made by simply rotating the spare, that it's still worth trying before spending money on throwing parts at it.

 

[DWaX]

Good Morning DWax,

I must Man-Up and state that I tested the camera by hanging a stick over the spare tire from inside the vehicle with a string that was hanging at the end of the stick, a string just long enough to hang over the camera but go no farther. This was not easy. It was I alone attempting this, I'm 6'2" and could benefit by taking some yoga classes. Anyways...

I engaged the parking brake, put the jeep in reverse, crawled to the back (because opening a door made the vehicle autopark), and dangled the string over the camera. I was able to see the string on the Uconnect screen and I did not get an alert. With these results, it substantiates your claim. I am now left with bewilderment. Per my previous tests, back when this post started, all my tests left me believing the camera was impacting/alerting the sensors. With my camera unplugged I was not getting alerts. Keeping the wheel & tire in the same position, I'd plug the camera back in and the alerts would resume. This is all baffling to me. None the less, as a man I must stay true. My latest test tells me you are correct, you added some knowledge to my cup. My apologies.
Hope you have a good Thanksgiving.
~justin

Man, I'm only sad you didn't get a picture of performing that experiment..... haha

 

[DWaX]

Still doesn't explain why only the left sensor was triggered when the stem was on the bottom left. When the tire was rotated by one lug position, only the center sensors alerted. And one more lug position got the same right side only alert.

If it's not the camera causing it, the sensors must be reading through the tire.

Either way you cut it, enough fixes have been made by simply rotating the spare, that it's still worth trying before spending money on throwing parts at it.

I won't pretend to be an expert in this area my any means, so I'll just make a few inferences.
I'm assuming there is a TPMS sensor just under that valve stem, this will emit a radio frequency. It is possible that RF Interference is triggering the sonic sensors in the bumper which can in fact be effected by RF even though they are ultrasonic, the frequencies are not that far off from each other. Internal filter circuits and shielding in the backup sensors is supposed to protect from this but who knows... maybe that tpms is whacked.

Test: Move another tire on the carrier and see if you get the same result.

WaX

 

[manapiko]

I'm going to move my spare and test this out tomorrow!

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