E34 540i mystery wire

[straight6pwr]

yes the OPs original photos shows that he has ASC and its already plugged in, so its not that.

marshallnoise, you have the same throttle body as the OP, he just has the ASC throttle unit in addition. i cannot tell the colors in your photo. your image of the engine harness with the german labels and the 'Anlasser' or starter may be a clue but the m60 starter doesnt have any plugs on in like that.

i'm guessing there is some optional accessory not on these cars like servotronic steering box or something that it goes to.

[jpod999]

i'm guessing there is some optional accessory not on these cars like servotronic steering box or something that it goes to.

Interesting that from the factory the harness has that unused connector.

[straight6pwr]

Interesting that from the factory the harness has that unused connector.

realoem suggests that all USA m60 e34s (530i and 540i both manual and auto) had the same engine harness. not surprising really, they did that other places on the e34s such as being wired for CD changer/car phone even if they weren't a chosen option.

[marshallnoise]

There are your wire colors.

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[straight6pwr]

ok after pouring through the ETK, i may have found something. its looks as though late production 530i e34s received a secondary air pump (for emissions) which has a check valve located on top of the intake manifold on the passenger side of the car. it uses that same black 2-pin plug, and would not be located on any 540i or early 530i. but since your car is a 1995 they would have added it to both 530i and 540i harnesses since they are the same parts. so any 540i produced after about June 1994 would have this dangling plug.

the ETM shows RT/BL and BR/BL wires going to the Secondary Air pump valve on page 1210.11-12 and those colors match your photo marshallnoise.

valve shown here on Realoem:

http://www.realoem.com/bmw/enUS/show...diagId=11_4953

boomgoesthedynamite?

[marshallnoise]

Boooooooooooom! Finally!

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[Gaode]

Wow. Finally. Haha. Good to know.

[Gaode]

Even tho it's already resolved, I wanted to post the pics I said I would anyways lol.

[jpod999]

Here's the secondary air page if anyone is curious:

[jpod999]

so any 540i produced after about June 1994 would have this dangling plug.

I have a harness out of a 12/94 production date 540i/6 and I do in fact have this plug also. It runs to a 50A fuse holder as well as a relay. I'm going to cut it all out of my harness including the unused connector. More info at the end of this post: http://www.r3vlimited.com/board/show...6&postcount=12

This thread has been super informative!!

[marshallnoise]

Guys, we fixed the internet. My good deed for 2016 has been completed.