I'm having fits with the ASR light on my 92 500SL as well. Mine happens when I coast for a while and usually AFTER it's been driven for a while. This morning it freaked me out and did it 2 miles from the house. It's never done it before getting fully warmed up before... I also have an intermittent skip at idle and a hesitation (single-cylinder miss) when I accellerate off of idle.

I am hoping my 3 problems are related.

I will be watching this post for ideas as well.

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02 S500
92 500SL
92 400E (Sold)
87 300E (Sold)
83 300D Turbo (Sold)
75 300D (Sold)
74 240D (Sold after 20 years)