c101 and x20 wire diagram (e30 M50 adapter)

[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

[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]

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

[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

[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!]

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

check your pms.

[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.

[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.

[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.]

I bought a blank E30 engine side connector and pins. I cut off the E36 engine side connector to expose the wires. I'll crimp the appropriate E36 wires and place them into the corresponding slots (according to the above pin chart) in the E30 engine side connector. The new E30 engine side connector (w/ E36 wires) will be attached the the E30 chassis side connector at the stock location. The unused wires I will cap off and secure under shrink wrap. I assume this is the proper thing to do, correct?

From the looks of my chart, I should have 5 pins (3,8,11,17, and 19) that are not used. The only two that had original functions with the E30 C101 are pin 8 - Fuel Rate Output to Motronic Control Unit and pin 11 - Service Indicator Reset.

[cahomey]

If it was easy, Treehouse couldn't charge $400 for an adapter.

They must custom make each adapter for your year car and motor right?

EDIT: I do have the ETM's for both cars, but I'm having trouble finding usefull diagrams.

[Mike B.]

You have to basically search each system page in the ETM's and look for the C101 and x20 connectors in the individual diagrams. Look at the pin# and wire color and compare it to the chart you are creating. If it matches what you have, check it off and find the next item. It can be slow and time consuming.

I really wish they had a pin chart for the C101 and x20 for each year. It would make this process a whole lot easier.

The chart I have listed above, as far as pins and wire colors is accurate for a late model '89 'i' and a 93 M50tu based on the ETM.

[Mike B.]

Here is the wiring diagram from the ETM for the late 89 and up ABS (Pin #20 Red/Yellow). You can easily see where you need to pull the power from off of the Main Relay.

[EtaSport]

So I was almost wondering if I should go through all the years and make some charts then use it as an ultimate wiring thread. It seems like everyone should be open to the info, but in the same time I dont know if I want everyone to benefit from all my time. thoughts? maybe if we split it up since lots of us in this thread know how to do it?

[cahomey]

This is the only thing I can find under "engine diagrams"



None of the engine harness sensors.

Can someone post a picture of a '90 airbag car c101.
Or diagrams for each of the engine components.

thx