About six months ago, I purchased a 91 300TE 4-matic wagon. Recently, the 4-matic light came on. Information as to what might cause this light to illuminate seems to be sparse. My owner's manual mostly says to "see your dealer" ... which, as best I can tell translates as "Open your wallet".

I found the hydraulic fluid reservoir, and I believe it is low, but I don't see any graduations to indicate how full it should be.

Any information is appreciated.

Thanks in advance,

LeonH