ABS,ESP again...

[sceh]

W204 diesel 2011 50K miles.
I get the ABS, ESP, DSC lights on randomly and when it happens the ECO light goes out and won't work.
Carsoft tells me there is a fault code C113000 L6/4 right rear electrical fault. However, the wheel speeds are perfect.
The car is left hand drive so right rear is which wheel (imagine you are in the driving seat - is it behind you or the other one?)
I also get U140D00 unreasonable wheel speed but this is no surprise as well as D40C (no CAN data etc)
If I clear the faults, all is ok, ECO works and this can last ten miles or 100 yards before I get the errors again. If I stop and restart the errors often disappear.
ANY ideas why this can happen?
I know a STAR visit might help but I am wary
I have changed the rear wheel speed sensors multiple times in the past but It could still be a duff sensor and since the speeds read OK, how can I tell?

I am lost

As a base question, is STAR better/more functional than Carsoft? A silly question perhaps but, for example, the IID Tool which you can buy for Land Rover is much more advanced than LR tools and the people supporting it more competent than LR folk. I am a little reluctant to ask for a STAR analysis but perhaps I am being stupid here because the rest of my experience with Mercedes has always been 'star'!

Some say that the key thing to do is to unplug the ESP module and clean the contacts btw

 

[sceh]

The plot thickens.
Start the car, don't move it, clear all the faults with Carsoft and just now and again the three lights 'ESP,ABS,EBD) will flash on for about five seconds then dissappear.
So, this is nothing to do with wheel speeds (since they are ok), nothing to do with reluctor rings either.There are loads of posts about the right rear sensor etc but it is not this as people who changes it soon find out.
Given the D40C, no CAN data and so on it points to a bad contact somewhere and by definition not at the wheel level or the sensor level.
Now I need to find it..

 

[sceh]

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[sceh]

Checking around the net I find dozens of references to the 'right rear electrical fault' when this error message arises and the warning lights come on.
This alone is curious. Why would it always be the right rear and not the left rear especially when the wheel speeds can be read perfectly.
Simple - it isn't the right rear at all and nor is it anything in the chain of events up to the ESP module. It could possibly be a chafed wire but Mercedes build cars properly so this is pretty unlikely in the majority of cases. It is a bad contact

 

[HITECH]

Checking around the net I find dozens of references to the 'right rear electrical fault' when this error message arises and the warning lights come on.
This alone is curious. Why would it always be the right rear and not the left rear especially when the wheel speeds can be read perfectly.
Simple - it isn't the right rear at all and nor is it anything in the chain of events up to the ESP module. It could possibly be a chafed wire but Mercedes build cars properly so this is pretty unlikely in the majority of cases. It is a bad contact

My own experience is front left more common ( regardless of left hand or right hand drive ) and seems to be the wiring, connectors. Also new ABS wheel speed sensors getting scanned at airports when they come from oversees get zapped by xray scanners lol. Crazy but true. Why so many people scratch their heads why their new wheel speed sensor is still fault ( assuming the wiring , connector issue has been fixed)

 

[sceh]

I think these cars are somehow connected to some higher being....
I decided to go and see the dealer to make an appointment and to have a chat about root causes.
Start the car, christmas tree lights, drive a mile, lights go out, get to the dealer and the lights are still out, drive home and the lights are still out...go figure.

I'll let you know. The only thing I have done is clean the ESP terminals with a cleaning spray