M30B35 Swap FAQ

[1st 5er]

Merry Christmas, y'all.

[willyv124]

I"ve read through this a few different times and i'm working on my 1.3 harness again getting ready for install. Trying to clarify something about the wiring diagram here



For the c103 wiring. it says

e28 c103....e34 c101....e34 dme
pin 1...........pin 9..........pin 6
pin 3...........pin 8..........pin 32

i.e.
pin 1 = pin 9 = pin 6
pin 3 = pin 8 = pin 32

and when looking at the ETM that works out for c103 pin 1


but when looking at the ETM for pin 8 and pin 32, they don't match. pin 8 of e34 c101 goes to pin 38 of the dme, pin 3 of e34 c101 is actually what goes to pin 32.



Looking at this, it does seem clear that pin 3 is actually what i want to get the fuel economy.
https://www.e30zone.net/e30wiki/index.p ... tronic_1.3

Can someone shed some light on this? Have I missed this in thread already?

[trancher]

Purveyor of these just replied to my inquiry:



I'm def getting one.

I installed this over the weekend, and it works great.



I installed it on the female side of C103, inline with the WT/BK wire that goes to the OBC. For power, I used a spare 12V from the main relay that was part of the B35 harness and was unused. For ground, I used the ground for the flashlight charger.

The potentiometer lets you adjust the signal to the OBC/econometer:

Keep the adjustment knob in the middle to start and get an idea of where your corrected mileage stands. Turning it to the left will increase your displayed mileage, turning it right will decrease displayed mileage.

I started with it all the way to the right and I showed 7-8mpg after a 4-5 mile drive. Then, with it all the way to the left, I showed 26pmg on the same loop. Putting it roughly in the middle it then showed 15mpg.

A few tankfuls of fuel and it will be easy to dial in. Great product; would buy again.

What is this thing called, is there any information, and where can I buy it?