Can anyone explain or show me a link that unravels the art of diagnostics using fault codes?

[Submariner1]

Sub, sometimes you over think things and make them more complicated than they need be.
Wheel speeds will never be identical front to rear unless every parameter is identical (wheel/tyre size, wear, pressure, tyre load etc).
If wheel speeds were an issue you would have the ESP light blinking away furiously as it tried to compensate for what it thinks is a wheel(s) that's lost traction.

Thanks Alistair
So I was on the right track ref front and back.
Good point on the blinking traction control triangle. Thats a great reference re wheel sensors.

 

[Botus]

how often do you get to drive the car

mine eats electricity in its sleep, I seldom use for 2 weeks at time... when I do drive I try to do at least 10 miles, but at this rate it really needs to be on perm trickle charge

every 2 weeks of non use, if you pop a charger on it, it will happily feed on 3 amps for 12/18 hours before the battery begins to think its happy

 

[Submariner1]

how often do you get to drive the car

mine each electricity in its sleep, I seldom use for 2 weeks at time... when I do drive I try to do at least 10 miles, but at this rate it really needs to be on perm trickle charge

every 2 weeks of non use, if you pop a charger on it, it will happily feed on 3 amps for 12/18 hours before the battery begins to think its happy

Hi Botus
I do 2,400 pa.
But often might not use the car for 2 days and then a 6 mile trip to shops.

I reckon if it was a daily drive of 15 mile each way to the office.
The low battery issue would probably vanish.

But thats not what I need to do.
Since retiring I drove an SL500 and then an inherited C270 cdi .... both these hacked it nicely with no issues.

 

[Botus]

there you go.... I've been away and the car's not run for 3 weeks, rear battery voltage (the 26kg AGM 2 year old one) 11.8v
If I'd turned the key the world would have ended seven times over.... put on charge for 24 hours and you don't need a merc dealer

 

[Botus]

2 miles will just deplete the battery till it plays up... as television used to say a 400 mile trip only just makes a dent in the battery charge state on these monsters

min distance of starting ANY combustion engine should be 10 miles... (but its not always convenient), my trips tend to be 6 to 10 miles even thought where I want to go locally is 2 miles to the shops or 3 to see my parents. Or, 2x 70 miles to give it a run, if I can do 3, 10 mile trips and 1, 70 mile trip every 2 to 3 weeks I can eek out the 24 hour 3 amp charge routine to once a month....

when I had the boot trim out years back adding the waste of space rear camera, an engineer at work couldn't believe the shear quantity of link wires and the gauge of wiring used... his comment was, " are you driving a power station? "