Partronic sensors - how do they work?

[hygt2]

Hello all

Parking my car day (work) and night (home) in parallel parking spaces have resulted in needing my 3rd new parking sensors in the last 12 month.

Where time I can see a slight scruff mark on my rear bumper and although the marks polished out, I am left with a malfunction parking sensors.

Now that I have 3 old ones at home, would anyone be able to explain to me how the sensor (4-pin plug) works? I am going to take a sensor apart and see if I can hopefully repair it. If it works again than I'll do the other 2 and have some spare sensors for the next broken one

Incidentally I have never had a front scruff, maybe because there is a protruding number plate holder.

Thank you very much in advance.

Garrison

 

[dnoyce]

Hello all

Parking my car day (work) and night (home) in parallel parking spaces have resulted in needing my 3rd new parking sensors in the last 12 month.

Where time I can see a slight scruff mark on my rear bumper and although the marks polished out, I am left with a malfunction parking sensors.

Now that I have 3 old ones at home, would anyone be able to explain to me how the sensor (4-pin plug) works? I am going to take a sensor apart and see if I can hopefully repair it. If it works again than I'll do the other 2 and have some spare sensors for the next broken one

Incidentally I have never had a front scruff, maybe because there is a protruding number plate holder.

Thank you very much in advance.

Garrison

Forgive my saying so, but why bother repairing them if you are not going to use them properly?

David

 

[hygt2]

Forgive my saying so, but why bother repairing them if you are not going to use them properly?

David

What do you mean? I use them all the time when parking or threading slowly through narrow streets with parked cars?

 

[GordonTarling]

I think the point being made was that parking sensors are there to stop you hitting things. If your sensors are getting damaged because you're not stopping when the sensors tell you to, you're doing something wrong. Conversely, if you're hitting something before the sensors tell you to stop, then something is wrong with the system.

 

[Swiss Toni]

I think the point being made was that parking sensors are there to stop you hitting things. If your sensors are getting damaged because you're not stopping when the sensors tell you to, you're doing something wrong. Conversely, if you're hitting something before the sensors tell you to stop, then something is wrong with the system.

Except it is other drivers without the sensors that do the bump parking, not hygt2....

 

[kay7]

This is funny indeed...i have parking sensors and never used them. A good driver is not using parktronic. I`m driving since 1994 and never had an accident or scratches on my cars...in your case i`d say leanr to park the car without sensors then use them...

 

[Diesel Benz]

I don't know if I read this incorrectly but I did not find hygt2 stating he was hitting some object, it could have been someone else hitting his car when it was parked. Those sensors get broken also if the car is parked if someone else hits the car.

But a small scratch on the paint may not be the issue, it can be the inner parts of the sensor.

What ever the reason for sensors failing, it would make sense to fix the old sensors if that was possible. If three have gone bad, one could expect some failing in the future again. I have never had a broken sensor and have not looked at those but I doubt one can access the failed part, be it mechanical or electronic.

 

[hygt2]

I think the point being made was that parking sensors are there to stop you hitting things. If your sensors are getting damaged because you're not stopping when the sensors tell you to, you're doing something wrong. Conversely, if you're hitting something before the sensors tell you to stop, then something is wrong with the system.

Sorry, I meant it was someone else's car bumping into the back of my car. The system works fine and when all the bars are on full the distance to the obstacle was about 2-3 inches.

 

[dnoyce]

Sorry, I meant it was someone else's car bumping into the back of my car. The system works fine and when all the bars are on full the distance to the obstacle was about 2-3 inches.

Apologies. I mis-understood your post.

David

 

[hygt2]

Apologies. I mis-understood your post.

David

No worries.

Are there anyone out there who knows how these sensors works and how they can be tested and rebuilt? I am keen to get started before I need to buy another one.

 

[GordonTarling]

My apologies, too. I didn't realise from your original post that it was other cars being driven into yours. I don't think there's anything repairable in the sensors, unless it's possible to swap the innards of one with a broken shell into another shell.

 

[et0609]

I believe they work by sending a radio wave which bounces off an object. The length of the radio wave is then measured giving the distance between the sensor and the object.

 

[FinstP]

The sensors contain a thin, brittle, piezoelectric crystal (usually quartz). This sends out an ultrasonic wave at 40kHz and also detects the signal reflected from nearby objects. The crystals are unfortunately very easily cracked by a bump and a cracked crystal can't be repaired. If you were very lucky one of the leads may have become disconnected, but the sensors are usually potted in some silicone rubber and are very difficult to dismantle without damage.
Anyway, if it isn't working, there's no harm in trying to take it apart!

 

[Smatt]

If the sensor is dirty, or if the paint on the sensor delaminates, then this will also cause a fault. So, always check sensor is clean if not working properly, although I think this will cause xs activation of proximity alert.