SLK/R170: Coolant!
The coolant light came on in my '99 once when it was about a year old. I added maybe 8 to 10 ounces of distilled water and it the light went out. It never came on again afterward in the 18 months or so before I traded the car. Several other people had the exact same thing happen. The coolant level sensor is fairly sensitive. The sensor is also prone to indicate low coolant when there isn't a problem. The reason is that they sensor is tied into the same circuit as the windshield washer fluid reservoir and if one sensor goes bad, it can report a problem for the wrong fluid.



