Love your C101!!!

[GunMetalGrey]

Awesome job sir, sticky for sure!
Only problem is now you are going to have people complaining that it does not tailor EXACTLY to their car lol
Good job on writing all of the functions! I learned a good amount from reading this!

[jjt]

Just wanted to stop by and say Many Thanks for this excellent info!

[BenjaminButtton]

Sticky

2nd

Awesome job sir, sticky for sure!

So sticky.

I didn't have any issues wiring mine, but this will make a lot of current swapper's lives easier.

[Dennis320is]

I really hope this thread is alive.
I have just built my own harnes for my S14 engine because i have changed out the motronic unit for a stand alone management. I have only one issue and it is the oil level in check panel. I can see pin 2 and 10 is going to send some signal to the panel but my panel shows that i have low oil. I have recently drained the oil and filled upp with exact amount of castrol edge 10/60 but it wont turn of. So i think the issue is the pins. How can i make this work?

[SmokeE30]

I really hope this thread is alive.
I have just built my own harnes for my S14 engine because i have changed out the motronic unit for a stand alone management. I have only one issue and it is the oil level in check panel. I can see pin 2 and 10 is going to send some signal to the panel but my panel shows that i have low oil. I have recently drained the oil and filled upp with exact amount of castrol edge 10/60 but it wont turn of. So i think the issue is the pins. How can i make this work?

try to ground the wire, that should turn the light off at least

[Dennis320is]

I will try this weekend. Wich one schould be grounded? 2 or 10?

[Bmwchronic]

so, i have a stupid problem.... i switched my c101 connector cap, from my other e30. it all started because i was trying to fix my tach. i have switched my instrument cluster from my other car into my turboed car with the tach problem and it still didnt work. so im suspecting its signal wire. anyways, the connector had one more prong on it, so i thought i would give it a try. Every since i put that different connector in, my car wont run. it tries to idle but it doesnt. it turns over and it fires very slowly, then shuts off. i have put my other one in and gave it a try but it still doesnt work. no fuses are blown either...

[Ether-D]

I just want to say thanks OP. Linking this to my build for reference.

[amcink]

Subacribe

[ck_taft325is]

Sticky or ban.

[18rabbit]

Ok, so when I went to wire my c101 connector to my e34 harness I ran into trouble because most user made diagrams did not match my wiring scheme. This thread got me through it though as OP had similar wire colors as me. I wanted to post my wire colors in hopes of helping someone else out:

Wire color on 'car' side of c101 for a 8/90 318is:

1 empty
2 blue/yellow
3 empty
4 brown/violet
5 black/brown
6 green/yellow
7 green
8 empty
9 empty
10 violet/green
11 white/blue
12 brown/black
13 violet/red
14 empty
15 empty
16 white/black
17 empty
18 black/yellow
19 empty
20 brown

[barry]

Well done by a class act. Thank you

[benz-tech]

If the mods wont sticky this then I'll just have to bump it with some accolades.
This page helped me re-pin my entire C101in about 2 hours, with each pin verified. BIG props to the op. The explanation of what each circtuit does makes a big difference too.

Id like to add that pin 14 is used on the later E30's for the VSS signal from the cluster. An absolute must for an OBDII swap, and possibly needed for some OBDI.

[e30_325es]

Bump for new pin 20 info. I just installed a 90 I engine and harness into an 87 eta chassis. Turned the key and smoke started coming from the main relay wires. Found the ABS power wire that runs out of the main relay to pin 20 is what fried. The body side has an unused ground at pin 20, and shorted out the wire. I cut the wire for now, and no more smoke was released. Eventually I will wire in a bypass for the ABS. On the 87 chassis, the ABS gets its power out of the over voltage relay in the fuse box.

The strange thing about this is that I have swapped an 89 harness into an 86 chassis with no ABS issues, so I never thought to check for this.

[nando]

that is a well known wiring difference. the 89 doesn't have any pin 20 because it doesn't have an airbag, which is why you didn't have a problem. airbag cars have different ABS wiring - the relay is on the ABS unit, and pin 20 is the power signal that trips the relay. When you plugged that harness into your '87, it connected 12v to ground and nearly caused a fire.