Rear parking sensors disabled 'cos of tow bar?

[Johnny G Pipe]

Hello.

Our new to us 2001 320CDI estate has an aftermarket witter tow bar and twin electrics.

The rear parking sensors don't work, which (after searching the forums) I'm hoping is because they've been disabled to allow towing without frantic bleeping at every traffic light..

We are only going to use the hitch for an occasional bike rack - If this sounds likely,can we get these sensors working again without removing the hitch?

Thanks in advance..

 

[Johnny G Pipe]

Ok, we're muppets. My wife has found the rear direction display, behind the driver obviously - as thats the direction you're looking when reversing.
We thought the dash indicator did both directions. We're from the country, you know...

 

[television]

Ok, we're muppets. My wife has found the rear direction display, behind the driver obviously - as thats the direction you're looking when reversing.
We thought the dash indicator did both directions. We're from the country, you know...

funny that you posted your answer,when I bought my SL I could hear the rear bleeper but could see nothing as the wind deflector was down and hiding it in the rear seat, the other problem that I have is that I am too tall to see in the mirror and the sensor window at the same time.

Malcolm

 

[survey]

Johnney G Pipe - I have a C class 220cdi estate. I am about to have an aftermarket towbar fitted (can't use the merc one as it will not accept my bike rack). I have tested the rear sensors by using a box hung out to represent the towbar and as far as I can tell my rear sensors are not affected. Can you confirm that the sensors will work with the towbar and ball fitted?

 

[whitenemesis]

Reading the handbook the rear sensors are disabled as soon as the trailer electrics are connected (on an MB towbar at least). The tow hitch would be too close to the car to trigger the sensors (min distance 20cm)

Not sure how an aftermarket towbar/electrics would interface with MB Parktronic system

 

[television]

This is why these things are joined up to the rear SAM and automatically turned off when coupled off, I am sure that an after market tow bar would still use MB electrics

 

[survey]

Whitenemesis - I am hoping that by NOT using the MB bar that the electrics connection may be different and thus not disable the rear sensors.

Johnney G Pipe - When you are not towing do your sensors still operate OK despite the towbar being present. Whitenemesis seems to support the findings I came up with that the bar etc would be too close to trigger the sensors. If I clear that hurdle then it is just a question as to whether the wiring of the black 7 pin plug (this is all I need) will cause the MB system to disdable the sensors. I only need the towbar for occasional trailer use and a Witter Bike rack plate (that sits behind the towball)

 

[whitenemesis]

This is why these things are joined up to the rear SAM and automatically turned off when coupled off, I am sure that an after market tow bar would still use MB electrics

You would hope so Malcolm but I've seen instals where the wiring has been simply Scotch-blocked into the tail ligh wires!!

 

[whitenemesis]

The sensors will only be disabled when the trailer electrics is plugged into the connector. You will need this function or else the Parktronic will alarm as soon as you select reverse, sensing the hitched trailer.

 

[television]

You would hope so Malcolm but I've seen instals where the wiring has been simply Scotch-blocked into the tail ligh wires!!

Then of coarse all of the warning lamps come on, with the MB plug in it takes care of the trailer lamps as well

 

[bigasotonuk]

Hi,
Can you not just simply switch the Parktronic off when reversing? On my W202 there is a switch in the centre console for this.

 

[Tyfaenor]

I have just fitted a bar and electrics to my 04 CLK W209.
The aftermarket kit which came from Right Connections fitted into the Mercedes SAM and works fine. In order for the system to recognise the trailer and stop the factory-fit sensors activating, I now need to get the system coded up, otherwise it will start beeping with a trailer hitched (this also enables a double flash rate of the indicators on failure.
These instructions were included with the kit, so it will be easy to get done. However, I have been quoted between £26 and £40 for this simple procedure......

As I also have a switch on my dash which can simply over-ride and turn off the sensors, so I might not bother with the coding due to the cost.

 

[*Thumper]

Towbars are generic ...... MB dont make towbars ......... Brink make em ............. if you have parking sensors ... there's 2 routes to go .............. pay extra( around £80 for the electrics to be diverted, when you hit reverse ......or .........if you have an isolation switch in your cockpit ...hit that everytime you go into reverse ............. towbar fitted for a 2007> C class, should cost you around the £300, for a flangeball ........... a swanneck is useless if you wish to use a bikerack ...... and flange mounted bikeracks are much safer than the strap on jobbies ...........

 

[Newton]

The sensors will only be disabled when the trailer electrics is plugged into the connector. You will need this function or else the Parktronic will alarm as soon as you select reverse, sensing the hitched trailer.

Do you mean that my sensors will work ok as long as I don't have my trailer and electrics connected? Don't know what make the sensors are. They were fitted by the garage as part of the deal.

 

[television]

Do you mean that my sensors will work ok as long as I don't have my trailer and electrics connected? Don't know what make the sensors are. They were fitted by the garage as part of the deal.

Then there is no guarantee what they will do if not the MB genuine sensors