ECU bring Hunt

[wyshyvanuk]

Oooops - that title should have been "ECU Wiring Hunt". While wading through the murky instructions to install a G-Power supercharger on my 2008 Z4M, I have found it necessary to add a relay to the ECU. The relay requires a 12V supply for the water pumps (I'm hoping that they are the heaviest gauge red wires), and the positive wire to the pumps (easy). But it also requires an ECU ground wire and a red-yellow wire from the ignition. I'm clueless about the location of the last two, and I'm a little reluctant to guess. Any insight would be very much appreciated. My ECU box appears below:

[Steeler]

Originally Posted by wyshyvanuk

Oooops - that title should have been "ECU Wiring Hunt". While wading through the murky instructions to install a G-Power supercharger on my 2008 Z4M, I have found it necessary to add a relay to the ECU. The relay requires a 12V supply for the water pumps (I'm hoping that they are the heaviest gauge red wires), and the positive wire to the pumps (easy). But it also requires an ECU ground wire and a red-yellow wire from the ignition. I'm clueless about the location of the last two, and I'm a little reluctant to guess. Any insight would be very much appreciated. My ECU box appears below:

I tapped my intercooler water pump into a spare wire in my ECU box.
The wire that looks like it's returned back into the loom in your picture is possibly an "extra" that is dead headed.

[wyshyvanuk]

Thank you, sir!! Are you meaning the RED/WHITE wire with YELLOW bands that's in the bundle wrapped in the gray label?
I've attached a picture of the ECU box supplied in the instructions from G-Power. It shows splices on a BROWN wire (ground, I assume) and a RED/YELLOW wire. It's that RED/YELLOW "ignition" wire that's hiding from me. And the, possibly incorrect assumption, here is that the wire color is the same in their box as in mine.
If the RED/WHITE wire with YELLOW bands is a possibility, is there a test that can be applied? FWIW, the G-Power instructions also mention that the "ignition" wire should be "terminal 15".
I will now search for my bottle of Tylenol ;~).

[Steeler]

I used a multimeter to determine a wire that is hot when ignition on.
I used a chassis ground as a ground for my pump.

And yes I do believe that yellow/white/red wire is dead headed if I remember correctly.

I can always open my ECU box up later today and snap a pic if that works??

[wyshyvanuk]

If your ECU shows how the wiring is installed, a picture would be FANTASTIC!! Your set up has the pump wired directly rather than through a relay? I've heard arguments for each, but I'm in favor of simple. I hate to have you open the ECU, but it would be very helpful. Thank you!

[Steeler]

No relay on my pump.
Pictures later.

[Michael9218]

Don’t guess. Study the wiring schematic.

https://www.newtis.info/tisv2/a/en/e...nctional-info/

[wyshyvanuk]

Hi, Michael. I'd previously unearthed the ECU pin-out at: https://www.newtis.info/tisv2/a/en/e...l-unit/Z8TkuuA
but I'm not familiar enough with the protocols to translate that information into actionable wiring. I'd like to follow G-Power's instructions but there's a gap between them and my ability.

[Steeler]

wyshyvanuk
The pink wire spliced into red white in my ecu box.
Yours likely different because of different computer.

Pics as promised.

[wyshyvanuk]

Well, different enough. I must break out my multimeter. Yay. My I assume that I'm looking for a wire that will show 12V with the key is position 2?
BTW, nice installation of the catch can. And thanks!!!