Reverse sensors not working? cany any one help

Hello I have a Mercedes Benz C class 2.7 CDI Auto tip 2001, its only done 58k and drives fantastic, I will be keeping it, I have not long had the car and need to fix a few bits to make it perfect! If any one could help me out?
The car has rear reverse sensors but they are not working when reversing?
The front parking sensors work fine so I was hoping the display on the dash board was all ok?
The systems works perfectly when parking forwards but never works when reversing?
I was wondering if there was anything hidden that might re set the rear sensors or re program the system?
Short of this I will need to put it on a ramp and start pulling the back apart to find the fault.

Many thanks
Joe

 

Isn't there a rear display on the headlining that you view in your rear view mirror?

 

Are the sensors aftermarket or genuine fitment.

If they are genuine fitment it might be worth getting the car put on a star machine to get the fault codes read before you start ripping the car apart

 

Hello and welcome......the sensors need to be CLEAN !!!***???......helpful eh!

Mic

 

sounds like you may have an aftermarket system ( nothing wrong with that as I fitted a set for £20 on my old W210 ).

The Merc system will simply refuse to work if a single sensor goes duff.

Had a similar fault on my W211, traced it down to a rear sensor ( AKA Developers guidance ).

Confirmed it with Merc, who supplied me with a new sensor, I fitted it in about 5 min flat.

Very happy, as it works as you slow down, a very useful aid around town etc.