Z4 ECU and Harness plug

I know probably a dumb question but where is the engine control unit located on the 2004 Z4 Roadster 3 litre

Also my car was missing the audio amp when I bought it, I am assuming the previous owner had the amp fry and chose to listen to the motor instead of tunes.
Anyway there is a single round plug that comes out of the amp harness that has no where to go on the new factory amp I have.
what is it for?


Thanks
Dave

Here is everything you need for your audio system: http://www.shipkiller.com/AudioSystem.html


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Thanks Walter but way too technical for me.
Just want to know what the plug is for I will post a snap shot tomorrow for clarity.
Thinking maybe electric antenna(not used) or ground(not likely)

Dave

Anyone

Picture?

You said you would post a picture!

Pics of the plug in question loaded in thread starter
Anyone know where he ECU is?

Dave

ECU is in the engine compartment, right side of the car (looking from the front) in a black plastic waterproof housing just in front of the firewall and just to the right of the brake reservoir.




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Thanks Walter
Any clue what the plug is in the picture?

Dave

I do but I need better pictures. Does the plug have two or three pins. They could be circular pins?

PS. Walter E. Williams is a noted economist and conservative.

There is only one pin
Kinda looks like an RCA plug but smaller

Dave

That description does me no good, really.

It could be X1770 that runs from the right Satellite B-pillar module (SRS AIR BAG system) to the battery safety terminal generator (think pyro knife)
http://www.shipkiller.com/images/Amp...20Locatons.png