Euro model 1992 500 SL

The ASR light is allways on once I start the engine and move forward 20 Feet. The ABS system is not working -= when I slam on the breaks to test it the wheels lock and skid.
The MB dealer swaped out the ABS control unit and changed the ABS sensors - still the ABS did not work and the ASR light still goes on...The MB dealer is sugesting to change the "potentameter"?? and the Activator Motor .... now ... at a high cost $2400 ... ?

Any suggestions ...?
Thanks
RA

Did they read the error codes or are they just guessing??

I concur with Yal, they should be able to read the trouble codes, unless I am wrong and this model won't store codes, but the ones that don't store codes should be older than a 92.

A few things I can think of:
Start the car and wait about the same amount of minutes as it takes to cover the 20 or 25 feet you say it takes before the light comes on. Or even longer, say maybe 30 sec or a minute, just to be sure. If the light isn't coming on if you don't move the car at all, it sorta makes sense that there is some problem with one of the wheel speed sensors, and yes I read that they were replaced. So maybe it isn't the sensor itself, but maybe in the wiring for example. They should, if they are an MB specialist shop, be able to establish a link to the ASR control module and read what the wheel speed sensors are reading, this should narrow down the search incredibly!
Another possiblity is sometimes certain wheel and tire changes will affect the speed sensor readings, so even if the sensors are fine, you can be getting some screwy readings due to the tire circumference being altered, especially if done unevenly front to rear.
If the throttle response is OK, and the engine idle is even, I wouldn't really think along the lines of the throttle actuator, yeah, that's some pretty expensive ammo the guy is utilizing in his "shotgun approach" to repairing cars.
Another outside possiblity, and PLEASE don't take this to mean "Gilly sez I need this part", OK, it's just a possiblity, is it could be either a voltage problem, ie a battery or alternator, OR a part you may have heard about called the "Overvoltage Protection Relay".
They really need to "ignore" the fact it's a Euro car and try getting a scanner on the car to find the DTC's and look at the readings for the wheel speed sensors, i think if they can do that that they could figure it out without all the guess work and expense. Unless there is something really weird about this being a Euro car, but they should be able to do better than this!

Gilly

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Thanks Gilly,

I did more invastigative work over the weekend - I had a mecanic my dad knows look at the car - After telling him the long story - he said the ABS LIGHT HAD TO COME ON IF THE CAR IS LOCKING WHEELS AND SKIDDING. So the first thing he did was take out the dash ... guess what ... the ABS light, was there anb it was good, BUT the socket on the board was scratched out as to avoid making contact with the bulb ... so --that-- is why the ABS light was not showing the falt, when I bought the car.

ALSO wheels did change, they had put on AMG 17" ... That woukld be anby easy problem to fix ...?

Hope to hear from you

Rgds

RALPH