c101 and x20 wire diagram (e30 M50 adapter)

[triggrhaapi]

Here's my wiring contribution for an s50 -> e30 m3 swap - might also help the m50 and 325i people.

http://www.cityofdust.com/s50/e30%20s50%20wiring.pdf

http://www.cityofdust.com/s50/e30%20s50%20wiring.xls

Confirmed, just now!! This is the correct wiring layout for the 87 325is. The C103 connector looks kinda like a 12v power connection from the inside of a computer case.

EDIT: Thanks Rev Engineer, you saved me a huge migraine headache, which I would have had if I had to try to read the electrical wiring diagram PDF for another minute.

[PiercedE30]

Heres mine:
1990 325is to 1992 525i
C101 - Function - X20
1 - Alternator - 25
2 - Oil Level (static) - 1
3 - Not Used
4 - Coolant Temp (gauge) - 12
5 - Oil Pressure Switch - 23
6 - 12v feed for diagnostic plug - 22
7 - Ignition (switched) - 21
8 - Fuel Economy - 24
9 - Engine Speed (tach) - 20
10 - Oil Level (dynamic) - 2
11 - SI Reset - 7
12 - CEL - 8
13 - Fuel Pump Relay - 13
14 - Speed Signal - 14
15 - Starter (unloader relay) - 15
16 - Diagnostic Plug - 19
17 - Not Used
18 - Voltage during start - 18
19 - Not Used
20 - ABS - 3

[triggrhaapi]

I read through the entire 50 or so page swap thread and found nothing helpful for me with s50 wiring in an '87 325is. It doesn't help because some of the wires don't match the '88-'90, some of them aren't used on my c101.

this is what I have.

'87 E30 connector, engine side.

1 Blue
2 Blue/White
3 Not used
4 Brown
5 Brown/Green
6 Green/White
7 Green
8 Not used
9 Not used
10 Blue/Yellow
11 White/Green
12 Grey mated to a brown
13 Green/Purple
14 Not used
15 Not used
16 White/Black
17 Not used
18 Black/Yellow
19 Not used
20 Not used

I think our cars use a modified early E30 M3 connector, the missing connections are in the glovebox on the C103 connector. I'm hoping this is the solution to my problem. This is the only known harness missing 8,9,14,15 and all functions seem to be moved to the C103 connection.

Hope this helps you!!

[Bimmer335is]

pm'd

[Mike B.]

PM me your email address.

[Bimmer335is]

that would help me out greatly.

[Mike B.]

If you need a copy of the ETM to track down the functions of these wires, let me know and I will send you a copy for the '87.

[Bimmer335is]

'87 c101 connection to s50 wiring harness

I read through the entire 50 or so page swap thread and found nothing helpful for me with s50 wiring in an '87 325is. It doesn't help because some of the wires don't match the '88-'90, some of them aren't used on my c101.

this is what I have.

'87 E30 connector, engine side.

1 Blue
2 Blue/White
3 Not used
4 Brown
5 Brown/Green
6 Green/White
7 Green
8 Not used
9 Not used
10 Blue/Yellow
11 White/Green
12 Grey mated to a brown
13 Green/Purple
14 Not used
15 Not used
16 White/Black
17 Not used
18 Black/Yellow
19 Not used
20 Not used

[FredK]

Thanks!

Sorry to hear about your track mishap. It sounds like you have a pretty sweet replacement lined up!

[Mike B.]

See the thread listed at the bottom of my pin chart. I and possibly others have experienced some backfeeding of 12v through fuse 13 (fuel pump) when connected through the C101 connector. I can't figure out the reasoning behind this and it doesn't make much sense, but it caused issues with the O2 sensor heater. When I bypassed fuse 13 and connected it directly to the E36 harness (Thank Jason89i for the fix) and the engine ran significantly smoother.

I had no 'check engine' light issues with my setup and I know it worked because it was coming on when the alternator was going bad.

Maybe I was just doing the stomp test incorrectly.

[EtaSport]

Mike what did you have to change for the smoother running? I'm not having a problem that I know of, but a friend of mine is that may be caused by this.

I can also add, my wiring, which might be the same as above, i'd have to pull my charts, has had no issues, my code reader works, and my Peak tool reset my oil lights. I dont have a check engine light with my cluster, but I was going to add a small bulb somewhere. I was also able to do the pedal test on the blue m50 car.

[Mike B.]

I updated my pin chart and uploaded it to my server. It shows what I used for my running swap and also takes into account the small change to make it run smoother (see thread link) - your 'quote' image is now adjusted to show this. The car ran great until the mishap at the track.

I did not have a code reader, so I couldn't check to see if that function worked. I was unable to do the 'stomp' test.

[FredK]

Taking into account what was posted in this thread and what I found in the ETM, here is an updated pin/function chart for the late model '89 / '93 M50.



p.s. It probably changed my orignal chart posted earlier in this thread because I wrote over the original file when I uploaded the image to my server.

Mike, did this configuration end up working? Can you read codes from the Diagnostic Plug, and can you do a SI reset?

From what I gather, it seems like E36 x20 pin 19 goes to E30 C101 pin 11...

Otherwise, this looks exactly like my wiring adapter configuration, except that I have an early 1989 325i, so I have no red/yellow wire coming out of pin 20.

[Rev Engineer]

Here's my wiring contribution for an s50 -> e30 m3 swap - might also help the m50 and 325i people.

http://www.cityofdust.com/s50/e30%20s50%20wiring.pdf

http://www.cityofdust.com/s50/e30%20s50%20wiring.xls

[e30_kid89]

aahh i see...well @ least the 318iS is covered..thats what i was worried most about..the e34 harness shoudnt be too difficilt - i havent really taken time to look @ it but its SOMEwhat similar to the e36 except for some wire colors & functions here and there.