[718Niko]

My parking senrors tend to see ghosts. often. They ll triger for no appearent reasons for a few seconds and vanish.
When I asked the dealer about it he just told me they are super sensitive and I could turn them off when driving.
Now at the time I was also driving a range rover and by default I could see the sensors off when not maneuvering so didnt think about it much.
But now my other car is an audi and the sensors are allways on and she dont see any ghost.
Any of you have that 718 sensor ghost seeing issue?

 

[DriveInHouston]

I believe that it may respond to emissions from parking sensors in front of it. I never had 'ghosts' with no one around.

 

[718Niko]

Good point, I ll pay attention to that.

 

[Steve48]

Mine go off once in awhile. Read on Rennlist that the Macans are super sensitive this way, and mostly triggered by Fords electronics. Sure enough, mine went off this morning and I was behind an Escape. Coincidence?

 

[duegatti]

I've had it happen occasionally, and it does seem to happen mostly when I'm in town in a line of cars.

 

[GregW]

Mine go off once in awhile. Read on Rennlist that the Macans are super sensitive this way, and mostly triggered by Fords electronics. Sure enough, mine went off this morning and I was behind an Escape. Coincidence?

Coincidence? Nope.
Mine are nearly always triggered by Fords--trucks and vans especially.

 

[johan]

Mine go off once in awhile. Read on Rennlist that the Macans are super sensitive this way, and mostly triggered by Fords electronics. Sure enough, mine went off this morning and I was behind an Escape. Coincidence?

Thats not a fault it is a built in safety feature!

 

[Barryng]

I believe that it may respond to emissions from parking sensors in front of it. I never had 'ghosts' with no one around.

I noticed the system on rare occasions causes alarms when stopped at a light and surrounded by other cars. It sometimes even does it in low speed heavy traffic. It is indeed responding to real things but all the other cars I have had seem to know somehow when an alarm is not necessary such as in heavy traffic or when stopped at a light. Had not previously thought of this but emissions from very close other car sensors may indeed be the culprit.

 

[jimmuller]

Definitely triggered by other cars. I never noticed what kind of car.

I wonder what technology car proximity detectors use. Infrared, acoustic, microwave/radar? Continuous or pulsed? They could use adaptive frequency searching if the problem was bad enough. Or a digital signature in a pulsed signal. Very modern-techie though.

 

[DriveInHouston]

Ford trucks is the most common offender. Some Lexus SUVs as well.

 

[RussellHodgson]

My car sees dead people!

 

[Barryng]

Ok, so exactly how do these sensors work? I always just assumed they were based on sound and the the question has idly crossed my mind wondering why they all don’t interfere with one another, but until this thread never really gave it any consequential thought. So, assuming the sensors emit some kind of active energy and process the return, and considering the huge multitude of vehicle makes/models encountered, how do they keep from interfeting with each other?

 

[DriveInHouston]

http://www.porscheownersmanuals.com/2017-718-cayman-manual/17/196/ParkAssist

In my old Mercedes MY01, the park assist turned off automatically once the car moved past 3 mph (5 km/h), something you could confirm on the park assist display. Looks like Fords, Lexuses and Porsches have them always on (unless you choose to have them always off), at least the receiving part of the sensor on the 718. The manual says that they turn off automatically at low speed forward.

My guess is that there are distinct ultrasound frequencies or patterns distinguishing the different systems, but (unfortunately) it looks like Ford's and Porsche's can communicate with each other. It doesn't happen all the time, so it may be leakage rather than shared frequency.

One of the Teutonic notices I find a bit disconcerting, says that you can deactivate the parking sensors with button A up near the mirror BUT YOU CAN'T REACTIVATE THEM MANUALLY .

So, what do you do? Turn the engine off and on?

 

[jimmuller]

One of the Teutonic notices I find a bit disconcerting, says that you can deactivate the parking sensors with button A up near the mirror BUT YOU CAN'T REACTIVATE THEM MANUALLY .

So, what do you do? Turn the engine off and on?

Huh? I just push the button again and AFAIK they start working. The button is more of a mute button than actually turning them off.

If it actually turns them off then doing so might do the other drive a favor by making his own alert sound stop. Truth be told, that's a favor I'd just as soon rather not do!

 

[DriveInHouston]

Huh? I just push the button again and AFAIK they start working. The button is more of a mute button than actually turning them off.

If it actually turns them off then doing so might do the other drive a favor by making his own alert sound stop. Truth be told, that's a favor I'd just as soon rather not do!

Porsche Digital Owner’s Manuals - Porsche USA

www.porscheownersmanuals.com

Maybe I am interpreting this wrong?

 

[Barryng]

I would think at least one emitter/sensor must be active at all speeds to support emergency breaking and the auto adjusting cruise control.

 

[jimmuller]

I would think at least one emitter/sensor must be active at all speeds to support emergency breaking and the auto adjusting cruise control.

I think adaptive cruise control uses radar, not the acoustic sensors. Acoustic sensors would not be precise enough nor have the range to be useful for emergency braking.

Porsche Digital Owner’s Manuals - Porsche USA

www.porscheownersmanuals.com

Maybe I am interpreting this wrong?

I think so. I'm pretty sure turning the system back on re-engages the audible warning. It just doesn't re-engage the cartoon image on the PCM showing the locatiion and severity of the threat. I believe (but wouldn't risk my life on it) that once the proximity event has been cleared, the next time you encounter one the PCM comes back on.

 

[Barryng]

I think adaptive cruise control uses radar, not the acoustic sensors. Acoustic sensors would not be precise enough nor have the range to be useful for emergency braking.

I fully agree with that but it seems like it must have been a very difficult engineering challenge to keep cars from interfering with each other. I can only guess that the radar signal of each car is encoded with a code unique to that car. I would also think there must be a standard that has been agreed upon by all the manufacturers and there is probably a manufacturer like Bosch that developed the system and licenses it.

 

[Treemagnet]

My car sees dead people!

Elvis or Jimmy Hoffa?

 

[jimmuller]

Elvis or Jimmy Hoffa?

Sam Darnold.