For whatever it is worth, I had the full Sportline treatment done to my 87 300E (shocks, lowering springs, sway bars, bushings, spring pads, Sportline tyre size.) and had no problems with any of the warning lights - ASR or ABS included. The MB parts only lowered the car about 1/2 inch total so this may not be definitive in ruling out the springs as the source of the problem. I have the impression that the ASR light stays on a little longer after I replaced the 195/65 tires with the 205/60s, but I may be wrong on that. Did you change tyres/wheels at the same time or earlier? Maybe the combination of wheels/tyres and lowering springs could cause this problem. Good Luck!!
87 300E, 65k miles