c101 and x20 wire diagram (e30 M50 adapter)

[Beej '86 325es]

On the E30 and E36 sides there is a green wire - this is for the DME Power from ignition switch, and that I've got hooked up.

There is also a green/yellow wire off of the E30 harness - this is for the O2 Sensor Relay power. This one probably would work just as well to hook into. Don't you think?

[bostonbmw]

I put a disclaimer saying it worked for me... cuz it did. Sorry it doesnt work for others.

Maybe they should post the modifications they have made to it, the year and model of their car, vanos or non-vanos, e34 harness or e36 harness.

-Addis

Is this diagram from the Electronic Trouble shooting manual?If so what page is it on? I looked through and did not see it?? My C101 is out of a 90 325 I think. It seems only about 60% of the wires are the same color/pin.

[jahnaboi]

God damn just read this whole thread and I'm a lost for words. BOOGALA BOOGALA. Damn, does anyone have a confirmed pin to pin for a 90' 325i to 95' e36 m3 x20? Yes yes, flame on me for not comprehending and applying anything I read within this 9 pages, but I just want a straight answer from you experts!!!

[jahnaboi]

Scratch that, I'll come up with my own.

[jahnaboi]

Guys, what should I do with the pin 20 (ABS) color red/yellow and pin 10 (Oil level dynamic) color blue on the c101? I believe the pin 10 color blue is for the oil level sensor but where do I connect it to on the e36 x20 harness? Also with pin 20 (ABS) what should it connect to? Should I just take the pins out and run it like that?

Bare in mind I have a 90 325i using a 95' m3 harness.

[bimerok]

If I remember correctly for the ABS you need just positive. I think I took it from O2 Heater relay (thats 1 of 3 relays on the engine harness).

As far as oil level sensor wires - you only connect them to the c101 as the brains of alerting you about low oil is on the body and not in the ECU. (2 wires go to c101 and 1 goes to the ground anywhere)

Good luck!

[jahnaboi]

So pin 20 of c101 could be connected as one with pin 6 (o2 sensor) right and both connected to pin 22 of the x20 connector?


Also for the oil level sensor wire (pin 10) just leave it hanging out the adapter like some have done in this thread?

[bimerok]

I can't recall for sure, but I think C101 pin 6 is a smaller guage wire that is an actuator for the relay. I made a "T" off one of the thicker guages from that relay and connected it to C101 pin 20.

As far as x20 pin 22 - i'm not sure why you need to connect something to it. pin 22 is a reverse light.

For oil level, just have 2 wires comming from your adapter (pin 2 and pin 10 i think on C101). Once everything else is sorted out you can connect the wires from level sensor then.

[jahnaboi]

Disregard what I asked earlier. You said I need a positive for the abs. Could I connect pin 20 to pin 7 of c101? (Which is ecu/dme/ignition power) which is a positive right?

[bimerok]

You probably could, but the thinking I had is I don't want ABS to be on the same loop with any other "critical" systems and draw any extra power away, so that's why I didn't use ECU, Fuel pump, or anything else. To me O2 heater relay was a solid power from non-critical component.

But like I said, if you take power from any other source it will probably still work fine.

[hoveringuy]

I connected my pin 20 of the C101 to with its own wire to the reverse light on the X20. Since the reverse light wire is no longer required, I followed it back up into the splice box and connected it to a red/white (switched +12) wire.

You get a dedicated wire for ABS and no external wires hanging out.

[jahnaboi]

I'm going to take it off the pin 7 on the c101 and splice it in with pin 13. If my fuel pump is working then my car is rolling. If my car is rolling then my abs is working. =P

[B3M2W5]

I know this is old but

Ok on an 88 is there much diff to the 89 and 90 or should this pin to pin diag. work

88 325 C101 to 94 M50 x20
1-25
2-1
3-X
4-12
5-23
6-22
7-21
8-24
9-20
10-2
11-7
12-8
13-13
14-14
15-15
16-19
17-X
18-18
19-X
20-3

You guys see any problems?

[SamE30e]

[bimerok]

Attached is my pinouts sheet from when i was doing my swap (1991 325i 4 door/1995 s50).

Enjoy, Leo.