Thank you all MBDOC, WOLFGANG, ML 320, Azinn .......for all the advice
I have the 2002 ML 320 Km 136 000
Here is the problem I have not done much: mostly excuses being; 2 small kids and the fact that my ABS ETC etc and eventually the engine light sensor only comes on when it rains, further complicated by the fact that I just rust protected the vehicle underneath and on 2 occasion despite it raining the above sensor lights did not come (I assume the Rust proof agent acted as a waterproof for a while) I did take a visual observation under the vehicle looking for chaffed wires etc but must admit I could have been more thorough - I was shocked to find the one sensor right rear wheel disconnected ???? - remember the Snap-On "obd" reader gives PO 500 "A" indicating left side fault code (and yes MBDOC and Wolfgang said; take it to Merc so they can run a diagnostic on the proper Merc machine and I think he further stressed that they run scanner on the transmission sensor port), however, the ABS, ETS etc. and eventually the engine light sensor are back on again with the rain and will probably stop illuminating the dash when it dries up again.
But now I have an additional/further problem, doing a one direction 560 Km road trip I had no problem Averaging 125 km/h and using speed cruise control but on the return trip on a perfect dry road with he speed cruise control on the cruise control The Electronic traction stabilizer (ETS) started flashing (thereby automatically disengaging cruise control) and on one or two occasion felt a miss/hesitation, but it was not a engine, plug misfire. Under load or acceleration from 100 km/h and up, the ETS - Electronic traction stabilizer would flash intermittently - there where no other lights illuminated on the dash like when it rains, when I pulled into gas station radio off, window open, I felt and heard a intermittent rubbing/grabbing notice and sound from my left front wheel, upon a roadside visual inspection of rotor and pads for obstruction – none find.
My conclusion, Its not a wheel bearing causing the speed soensor to act up as there is no Whining noice eminating from and when I raised the front of the vehicle there was some play on both front wheels at 3 and 9 position, I assume now that there is a front left speed sensor or wiring problem from this point to the fusebox and is sending error code to the computer telling it that I am loosing traction on the front left wheel and braking as a result but I thought the ETS only engages up to 80 Km/h - if so must be real screwed up sensor
Conclusion I hope to do a better visual inspection for chaffing/short and remove Front left wheel and check under fuse box. And thanks to Nisan for you’re good advice OHM meter check on all three sensors remember the right rear one is disconeected - thank you
My reservation to follow MB DOC wolfgang ..... advice yet: is that it has been my suspicion that a wire/electric problem can take many hours and that the Technicians labour book does not specifically say how many hours, perhaps I should tel merc and find out how much it is to run diagnostics (presumably 1hr labour) and what’s the maximum labour that can be charged after that and lights only come on in rain.
So I think I am going to give it one more stab (do I wish I had the WIS or factory manual now !@#$~#$!#$%!) taking the above into consideration and IF I FAIL recognize defeat and call the MERCEDESE MINT Dealership
Thank you all those for their wonderful posts.
I found the problem some time ago - (sorry for the delay) on my ML 320. It happens to be the brake sensor wire chaffed and the wheel speed sensor wires chaffed behind the left rear wheel.
as the wires cross the left main frame and along the gas tank.
The first pic (specifically the corroded area) is the offending section.
Attached Thumbnails
Here is a link
http://www.peachparts.com/shopforum/...mith007&page=2
BAS EST and ETS warning lights ON '99ML320
