speedometer sensor 2nd try
 

Where is the speedometer sensor for a 1991 560SEL (126)? This is an electronic Speedometer.

Martin:
This seemed like an easy one. Until I popped in my 126 CD. MAN they really hide this info, I had to look at quite a few diagrams until I decided on this answer: I believe it's called L2, they say the left rear of the transmission, so roughly where the older version would have the cable attach? Maybe even fits IN that hole in the tailpiece. Looks like the wiring may somehow go through the same connector as the neutral/safety switch. Goes up into the speedo (there was another wire for this too, but I had to resort to a "spaghetti" wiring diagram and ran out of patience. Luckily the one I DID chase down went to this L2 speed sensor. From the speedo (I found out by tracing even MORE wires!) the speed signal generated by the speedo is shared with various systems, such as the radio, climate control, cruise control, engine control module, etc. My first thought was the ABS shares the speed info it gathers from the wheel speed sensors with these systems, including the speedo, but that must have came later.

Gilly

Gilly, Thanks I have given my brother my cd's as he has a 300sel and I just sold my 560 SEL. I am trying to help the new owner with it and will probably pick up the cost as it has been flacky for a while, I did warn him but it seems to be worse on rough roads and windy conditions which he is finding more common where he drives. I am hoping it is the sensor as opposed to a loose wire as that sure sounds easier to track down. Any idea on the part number for the sensor or is it actually in the tranny ( I hope not). And thank you for your reply it is greatly appreciated.
m

Looking at the wiring diagram, it appears the speedo, cruise control, ACC, radio, fuel pump relay, CIS controller and idle controller all take a speedo input. It would be strange if a problem downstream of the speedo gauge itself would have no other manifestation. At the very least if the cruise control works when the speedo is flaky then the problem is in the speedo itself.

I didn't find any information of what goes on between the tranny and gauge. I know there is an inductive cable that looks like a speedo cable with no gear at the tranny end, and a device behind the speedo gauge that accepts the coaxial conenctor at the other end of the cable.

Sixto
95 S420
87 300SDL

Sixto,
The cruise disconnects as soon as the speedo losses signal so you are correct, i did put that in another post which did not get me the answer i was looking for. Gilly nailed it and I found the harness part in my parts cd so it is atleast available. I just hope it is a loose cnnection.
m