Hi there to everyone !
After reading quite a few messages on this forum I noticed that my problem with the ETS/ABS lights coming on is anything but a "Rara Avis" for the ML owners and I have the feeling that there must be many others that went through some similar problems.
What I am trying to do is to come up (following your input) with some common-sense step by step troubleshhoting procedure for this kind of problem and hopefully it will become a main reference thread for newcomers.
So lets say someone who believes in the saying "If it ain't broken, don't fix it" and/or who thinks that finding some underlying issues before replacing a $1,600 ABS/ETS unit may be worth spending some time, wants to start with checking the simplest thing first and then progressivelly go to the more complicated ones. What would you think the order should be ? (i.e starting with number 1, 2, 3,...and so on. I heard break light switch, K25 relay, bad soldiering contacts,... .
Also, like I said feel free to share any weird simptoms and temporary or definitive fixes you found.
Thanks a lot!

Last year I experienced the ABS/ETS/ESP issue. Mine is a '02 ML270 cdi with around 90,000 kms on the clock at the time.


My symptoms were as follows:

One day while driving the ABS/ETS/ESP light came on and stayed on.

I tested the brakes on loose gravel - and sure enough ABS wasn't operating - the wheels would lock.

By simply switching off and re-starting the car, the warning lights would go off. Now if I brake ABS does work - but this would cause the lights to come on again! ABS would then not work again until the next re-start!

The dealer re-produced the problem and retrieved the diagnosis codes off the computer - i forget what they were but they felt that the computer needed replacing: several thousand dollars.

I drove around in this condition for a couple of weeks while getting quotes and waiting for my extended warranty company to get back to me.

The good news is on one of the forums i read about someone saying the lights can go on if the brake fluid is too old. Sounded too good to be true but sure enough - the problem vanished after the fluid was changed and has never recurred (now 12 months later).

In my case it was a ridiculously simple fix - worth considering if the symptoms are the same as mine were - saved several thousand dollars.

My ETS light has been on for a couple of years now.

It just means my cruise control won't work any more. Big deal.

__________________
Michael LaFleur

'05 E320 CDI - 86,000 miles
'86 300SDL - 360,000 miles
'85 300SD - 150,000 miles (sold)
'89 190D - 120,000 miles (sold)
'85 300SD - 317,000 miles (sold)
'98 ML320 - 270,000 miles (sold)
'75 300D - 170,000 miles (sold)
'83 Harley Davidson FLTC (Broken again) :-(
'61 Plymouth Valiant - 60k mikes
2004 Papillon (Oliver)
2005 Tzitzu (Griffon)
2009 Welsh Corgi (Buba)