any one know this part?
 

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Attachment 337
this plug has been there since we purchased this 325is a year ago, car seems to run fine just wondered what this is.
comes down beside the auto tranny.
It's harnessed together with a large cable until it gets down right before the tranny,
& then there is like 2 foot hanging loose with the plug. & I cant see anthing for it to plug into.
The large cable goes on to the rear on top the tranny.Battery?
After removing the alt, I can see it originates up under the intake to somewhere. I can tell enough to see it is not going to the engine coolant sensor or the or the other temp sensor, not the vanos, or the mass air.although any of those I would notice right away, I think. well the car seems to run alright, milage is a little poor at 19mpg,
it has 2 wires (1) BROWN (1) WHITE-WITH- GREEN STRIPE.
:dunno
thanks

What a mystery if everything is working. My guesses (yeah like they help) oil pressure sensor or speedometer connector :dunno

seems like it's reverse switch...... :dunno

yea check and see if ur reverse lights work

yeah reverse lights work ok,
tail lights, turn signals, trunk light, fuel fill door all check out.
on realoem.com there is a PULSE GENERATOR, SPEEDOMETER sensor? on the rear end, but it looks like it is connected, & my speedometer works well.
Aso on realoem.com, it shows another pulse generator just in front of the output flange on top of the rear of the tranny, but I havent fout a way to get to it to see if any thing is plugged in to it.

Your speedometer sensor is on the differential, not the transmission. It probably went to your EGR valve, which would actually be up in the engine bay.

It's either as Rob mentioned or the leads from 02 sensor (they're usually run along top of trans)

I thought m50's only have a non return valve, & no egr system.
02 sensor is plugged in, it is a 94 build so I believe it is ob1, & only having (1) 02 sensor, it should give an error code on the obc, if it were unplugged.
thanks guys.

It's kind of a toss up - none of us were aware that it's had an engine swap. I'd check with previous owner of who did the swap and/or source of running gear - the check RealOEM.com for wiring diagrams

sorry, its a 1995 325is, with a 12/94 build date.
Well I got bored this morning & really went digging for the source of the wire, & I traced it to this plug that was covered with elec tape,in the DME compartment.
Thing is I still dont know what it is.
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thanks you guys for helping this newb, Love this board!

Here's what I found:

Brown is always ground, goes w/o saying. White-green only appears on the '96 E36 (except M3) schematics, and is shown as "PROG VOLTAGE" for the transmission control module (EGS). I assume it is for functions that you don't have on your car. But I don't know why you'd have the harness in the 1st place . . either your DME or tranny was replaced?

Also, some auto transmissions had a speed sensor located at the top of the tranny. Not necessarily related to the speedometer; it may be for the tranny electronics for shifting purposes, I'm not sure. But the Bentley's tranny removal instructions say to unplug it, if applicable. So that means you may or may not have the receptacle at the top of the tranny.

In either case, who knows why the harness is there; looks like you may have a "Frankenstein" car (different parts repaired/replaced from different years). But but if everything works, then I'd leave it as is.

Thanks Dudesky for the info, like you said I am going to leave it as is.
Neither end is connected to anything.
Not broke, don't fix.

Does your temp sensor work on the OBC?