Questions about transmission

[Phatputer 3]

Quick one for you guys,

I am trying to identify the plug on the left side of this Automatic transmission, picked it up from someone who did a manual conversion a number of years ago so no chance of tracing the original plug / car.

It is for an M20 , going back into an E30 that was previously manual so no plug like it.

What is it, do I need it?

http://imgur.com/a/Wicss

the car used to be a manual M20B25 which I stole for my coupe, ended up with this engine and this transmission.

[humguy 9]

This might be one of those elctronic transmissions that the 2.5 litre engine had. It has its own wiring loom and ECU to control it. I believe that with out all th ewiring and ECU these transmissions will not function.

[HELLBM 1555]

Reverse light plug.

[Phatputer 3]

Don't think so, when I grabbed the engine I left that transmission behind, it had a large cluster of wires heading to the gearbox, this is just a two pin plug.

[Phatputer 3]

Reverse light plug.

In that case, have you got a plug I can buy?

I was going to run some tests tonight, throw it into reverse and see what readings I got out of that plug.

[Phatputer 3]

Did some checking, plug is showing continuity across both pins no matter the gear I am in.

did some cleaning and now have a transmission model.

Added to the gallery

4HP-22

[_ethrty-Andy_ 2132]

hmm im stumped, never came across that before, or maybe just never noticed. certainly never unplugged anything out of it.

its not a sport automatic box, my e30 had that and it would be an 8 pin connector.

i would have said its not the reverse light switch, but seeing Ray said that, its possible its the reverse light switch, but usually on an E30 automatic it comes off the switch built into the shifter.

Only thing i can think of is its for electric torque convertor lockup, but i didn't think that was available on BMW versions of the box.

for reference, E34 M20 use same box as E30 if you were wondering if there was a difference, at least the ones i have pulled apart.

[_ethrty-Andy_ 2132]

do you know chassis code of the car the box came out of? just doing some research now, looking like its some south african thing.

Seems to be a related to road speed calculation to help trans work out what gear it is in, working with the kick down etc.

But thats only one source, can't find much info about it.

Edited February 4, 2015 by _Ethrty-Andy_

[polley 916]

do you know chassis code of the car the box came out of? just doing some research now, looking like its some south african thing.

Seems to be a related to road speed calculation to help trans work out what gear it is in, working with the kick down etc.

But thats only one source, can't find much info about it.

Yeah. Seems weird though, has no other pins for valve body control. Ie, computer wouldn't be able to kick it down. Could be tcc lockup based on road speed.

[Phatputer 3]

Thanks guys,

I got this so many years ago out of some guys garage after he was cleaning up, the e30 it had come from had been sold at the time but I suspect it was a SA model based on what I have been reading.

At this stage I am going to leave it and hope it doesn't cause me too many problems with the shifting,

Will let you know what findings I come up with probably after the weekend.

[Phatputer 3]

Engine now in car, few more things before I can test the transmission.

but for anyone interested we think we found what that connector belongs to

http://www.realoem.com/bmw/showparts.do?model=1422&mospid=47283&btnr=24_0491&hg=24&fg=20

So the question really will be if the kick down is locked now or unlocked , and if without the unit it just won't lock.

[Phatputer 3]

And so if anyone else is looking this up wondering, it would seem not having anything plugged in doesn't prevent the gearbox from kicking down.

Tests this evening still allowed the gearbox to kick down with nothing plugged in.