Parktronic sensors switch off

[Bilko]

After starting the car or driving for a very short while my parktronic sensors switch off and the LED on the "disable" switch on the dash comes on.

The sensors are all clean. A relay perhaps ?

Any ideas greatly appreciated

Thanks

 

[whitenemesis]

Parktronic deactivates at speeds above 18kph or if Park is selected

 

[Bilko]

realise that but this deactivates on my drive whilst in reverse OR subsequently bleeps whilst driving and the LED deactivation comes on !

Bit bizarre I know....

 

[A-GALLY]

I seem to have the same problem (2001 e class w210)
They seem to work after a dry spell but if they get wet they just turn them selves off by lighting up the red segments on the display with the buzzer sounding and the red light on the on off switch turns itself on.
If you go to turn them on the buzzer sounds and the two red segments light up for about 8--10 seconds and then the switch light comes on again and the display goes dead.
I have cleaned the sensors but I think it must be a loose connection some where but I cant find it.
Under medium to heavy braking is when mine seem to go on the blink, I dont know is this a fluke but it seems that some little wire some where looses connection when under braking conditons.
If you have any luck please let me know, its driving me crazy:-confused:

 

[Bilko]

That sounds like it !!!!!!!!!!
OK the hunt is on - out will come the WD40 behind each bumper sensor and I'll let you know how I get on

Thanks

 

[bigasotonuk]

Hi,
My C43 does this too, i believe that it is one or more of the bumper sensors gone.
Can anybody tell me where sensor loom plugs into the car loom as i believe my front sensors have become unplugged and i dont want to unessacarily remove the wheel arch linings.

 

[A-GALLY]

do the bumpers have to come off and if they do how?
or who or how do you check the sensors and if only one is faulty would this knock out the whole parktronic system

 

[Bilko]

Managed to get WD 40 on to the rear of the sensors but problems still persists. Checking the continuity of each would now seem the next step. Is the faulty one open or closed circuit fail - anyone know or as mentioned earlier, how do you check ?

 

[whitenemesis]

On my set-up (MB after market fitting) the display will indicate if one of the sensors fails by constantly illuminating the revevant segment.

 

[A-GALLY]

cmon lads some body must have a bit more info on this

PLEASE

 

[FIBAMAN]

You will not necessarily be able to check continuity as these (I am am guessing) are either inductive or capacitive (something like that - the memory is fading) proximity sensors which will give out an electric signal possibly between 0 -12v depending on how close the obstruction is, the signal is then translated into lights / buzzers of varying intensity, to give warning. They have been used in industry for a multitude of purposes for longer than I care to remember. If it was my problem I would firstly try looking for something obvious and then probably resort to trying one new one in succession (like we used to do with old style christmas tree light bulbs) to find the duff unit.

 

[A-GALLY]

Fixed at last (maybe a fluke)

After several attempts I think my parktronic is working again.
I dont know if it was a complete and utter fluke but all I did was remove the near side iner boot liner and found the wires leading to the sensors on the back bumper, you will see them comming up from the bottom of the well space as if they are comming from under the car and gave them a twiddle.
I did not find them to be loose but as soon as i moved them i heard the buzzer from inside the car and they have worked since (2 days)
It just seems to be a loose connection.
My car is the w210 e class saloon.
Dont know if this will work for any other partronic problems but it seems to have fixed mine and now I am a very happy Paddy.
Let me know if this works for you.

 

[Bilko]

You will not necessarily be able to check continuity as these (I am am guessing) are either inductive or capacitive (something like that - the memory is fading) proximity sensors which will give out an electric signal possibly between 0 -12v depending on how close the obstruction is, the signal is then translated into lights / buzzers of varying intensity, to give warning. They have been used in industry for a multitude of purposes for longer than I care to remember. If it was my problem I would firstly try looking for something obvious and then probably resort to trying one new one in succession (like we used to do with old style christmas tree light bulbs) to find the duff unit.

Yes you're right. Contact with "a helpful chap at Inchcape Mercedes" said similar - the output of the working unit should ramp from 0-12v dependant upon proximity. I've suspended the job till the weather picks up and I can get the bumper off. The units are £44 each and my local Mercedes wanted £212 all in to do the work !
Will let you know how I fare as soon as the outside temp gets into double figures !

 

[FIBAMAN]

Managed to get WD 40 on to the rear of the sensors but problems still persists. Checking the continuity of each would now seem the next step. Is the faulty one open or closed circuit fail - anyone know or as mentioned earlier, how do you check ?

I do not think that this will give a simple open / closed signal. These units are proximity sensors which will give out an electronic signal of varying strength, hence the scale of proximity on your dash.

 

[Bilko]

Indeed - I should have emphasised the "ramp" as being a graduated increase from 0-12 dependant upon proximity. Hence the LED graduations on the dash as I presume each goes off at varying thresholds up to 12V and obviously dependant upon proximity. This would all seem to make sense

 

[BlackC55]

Remove the senhsors and test the resistance of the two outer pins. Compare them all and the faulty one will show up.

 

[Bilko]

Remove the senhsors and test the resistance of the two outer pins. Compare them all and the faulty one will show up.

That's Brilliant - thanks

 

[A-GALLY]

Just to let you know that after cleaning the connection in the boot as discribed above my parktronic is still working 100%.
Might be worth a go before you start removing bumpers and the like.

 

[Bilko]

Just to let you know that after cleaning the connection in the boot as discribed above my parktronic is still working 100%.
Might be worth a go before you start removing bumpers and the like.

I catch your drift - indeed, it would be rather demoralising to strip the bumper to find the primary connection to be the fault !

Thanks

 

[A-GALLY]

Still working