c101 and x20 wire diagram (e30 M50 adapter)

[EtaSport]

Dont forget what we talked about that you need to make sure that all the pins in your "adaptors" are all there, and they all go to the right pin on your e30 body side and all. Like I mentioned, most of the stuff is wired up correclty, but its the obvious stuff. I know a little more about the system though, and hopefully we can find a solution to the no start.

[Mike B.]

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.

[The Fast One!]

ok ABS isn't hooked up,

SI reset isn't hooked up

speed out put hooked up worng


none of those would make the car not start in my opinion BUT the two oil level lines are hooked up and they prolly shouldn't be but I don't know if that would keep the car from starting.

[The Fast One!]

i'll do it tomorrow morning and give it a try, dont work until 1:00

check your pms.

[EtaSport]

ok mike.. Im pretty sure I've got this down.

e30-e36 (function)
1-25 alternator
2 oil level static (not used on e36)
3x
4-12 coolant temp
5-23 oil pressure
6 e30 o2 sesnor relay power, e36 o2 relay hot at all times
7-21 Starter input (2 wire on e30 I believe
8-24 fuel rate
9-14 Tach
10 dynamic oil level (not used on e36)
11-19 SI reset function
12-8 check engine light
13-13 Fuel pump relay
14-20 speed output
15-15 unloader relay
16 SRS diagnostic connector, not used
17x not used
18-18 Starter
19x not used
20 ABS (attach as described in above post)

This should be it, ive gone over these things many times now. Everything matches up now, so give it a shot.

[The Fast One!]

thanks for mentioning about the ABS system, thats what i thought i had to do.


jon heres the wires for the m50

1 -----
2 -----
3 ----
4 black/blue
5 black/gray
6 violet/gray
7 black/violet
8 gray
9 -----
10 blue/yellow
11 brown/yellow
12 brown/violet
13 green/violet
14 black/white
15 black/green
16 white/yellow
17 white/violet
18 black/yellow
19 white/green
20 black
21 green
22 green/white
23 brown/gray
24 white/black
25 blue

[Jason89i]

The red/yellow wire is for ABS.

correct. the 90+ years run the abs power off the main relay.....no abs relay. so, you will need to tap a heavy gauge wire off the main relay for switched power. the easiest place is the crimp splice (where all the red/white wires come together in the harness.) run the new wire (main relay switched power) to the red/yellow that feeds the abs system.

cheers, jason

[EtaSport]

I sat down and made a chart for an 88 engine side, 89 body side, and 93 m50 side. However, I'm going to need the wires in front of me to verify years and pin numbers, mike. I havent checked the 94 yet, but I'll wait unless you can give me a list of every wire for each of your plugs. Indeed I found many things different in the charts I was looking at.

edit- mike your body side e30 color chart checks out as LATE PRODUCTION 89, and 90 model years. The red/yellow wire is for ABS. Everything else checks out. I will try to make a list of what everything does tonight, and then start looking at the x20 stuff.

[Jason89i]

I am about at the same point in my swap. I think it is a great idea to get all of this information into one location for future swaps.....]

just be cautions on lending out information......most people just want the quick easy route, just to jump pins, then whine if it doesnt work right and have know knowledge of how to fix it.

your diagram looks like a good start.....i added verbage like " STARTER signal from ign. sw to starter." it made it easier to follow, and more logical to connect pins.

e30pin7-GRN = ECU power from ign. switch.
e30pin15-GRN/BLK = signal from starter to K5 / K7 unloader relays (body electronics like pw/pdl.)
e30pin14-BLK/WHT = ROAD SPEED signal from the speedo to the ecu.
e30pin9-BLK = ENGINE SPEED signal from ecu to tack.

check your pins for OIL LEVEL. one is dynamic, one is static. if you get them crossed, no workie.

cheers, jason

[Mike B.]

The wire color for the coolant sensor shouldn't make a difference. As long as you know that pin 12 on the M50 is for the coolant sensor and it goes to pin 4 (coolant sensor) on the E30.

Colors help identify the wires, but what we really need to do is match function to function.

[The Fast One!]

looks good, once i find out some more info on them, I'll add to the chart as well.



EDIT- i just noticed, i have the same plugs but my pin 12 on the m50 is brown/violetinstead of brown. and my pin 14 on e30 is blue/yellow and not black white.

is this going to make a difference, i'll double check the colors just to make sure.

[Mike B.]

I am about at the same point in my swap. I think it is a great idea to get all of this information into one location for future swaps.

The engine side is from a '94 M50 and the body side of the E30 plug is from an '89 325i Automatic (5-spd conversion). I noticed that I too have the red/yellow wire for pin 20, so maybe it has something to do with the Auto transmission. The colors are accurate as they have been triple checked.

There are some gaps and any information that may fill in the gaps would be great. Once the chart is complete and the engine starts, I'll post a finalized version.

Here is what I have so far:

[The Fast One!]

jon- I did want a chart with everything already, BUT if i have to trace them then it is not that bad, just time consuming.

because of wire color changes, i'll ignore the wires in between the adapter, and line up correct pin for pin on the engine harness and the e30 body side.

jason-are ALL the colors for my e30 body side the same for ONLY 90+ cars, thats really wierd.

but this car is kind of wierd, we think someone did a 5-speed swap before i bought it and who knows what else.


once i get the diagrams and my own apater made i'll be posting a thread for sure about whats going on.


I might be taking my time though, found a 300zx I want to talk my dad into letting me buy and then the e30 would be a "fun" car that would get extensively overhaulled and modded.

[Jason89i]

Looks like your connector is an 88 which is the car you took it from. .....

are you sure? check pin 20. the 88-89's its brown.

Mike, I already found differences in your wiring using the etm. Perhaps this is the problem as to why the car isnt starting.

its incouraging to see someone out there that is willing to do a little work and not just look for "the easy way out."

.... ie-once you adapt the e30 side to the m50 side, you'll have to adapt the e30 side to your e30 body side.

dont forget......wire colors WILL change at the c101 for many functions. ie.....pin 5 is BRN/GRN on the engine side but BLK/BRN on the chassis side. it happens in 3-5 places, depending on year. of course it shows this on the wiring diagrams. its just that most people (myself included) dont think to check.

cheers, jason

[EtaSport]

i meant i believe hes looking for something that will show him the plugs straight out, not something he has to trace wires for.

Mike, I already found differences in your wiring using the etm. Perhaps this is the problem as to why the car isnt starting.

I just got etm for every year e30 and every year e36. Looks like your connector is an 88 which is the car you took it from. From what im hearing you may have to adapt your adaptor to make sure everything is correct. ie-once you adapt the e30 side to the m50 side, you'll have to adapt the e30 side to your e30 body side.