Thanks guys. I knew there was someone out there who can help. On my '97 CL600 I have ESP, ADS and I think ASR. I'll have to look. I have a little shrine in the garage with a candle burning to the Mercedes gods in the hope that I never have any trouble with these systems. Changing the fluid in the reservoir and a new filter are mandatory. I labor under the delusion that Mercedes knew what they were doing when they designed/installed these systems and it is up to us to keep them in tip top shape.
Anziani