c101 and x20 wire diagram (e30 M50 adapter)

[nando]

brown violet

O2s have their own power, yes

interesting fact: late M20 harnesses have both brown/violet and brown/yellow connected to the coolant temp sensor (cluster), but the brown/yellow wire doesn't go anywhere..

[Mr.SWISS]

Anybody willing to lend a second set of eyes to look over this real quick. The OBD2 isn't as well documented trying to change that. Pins/wires are varying slightly from pre 95 e36's.

[328ijunkie]

Few things i see. Recheck where C101 Pin 7, 12, 14, and 20 go. You have them going to the wrong places on the X20.
Hint: 2 of the wires arent on the X20 theyre on another connector
;)

[nando]

you don't need the brown/yellow wire either. the E30 sender/cluster only uses 1 wire. there's no pin to connect the brown/yellow to.

[Mr.SWISS]

you don't need the brown/yellow wire either. the E30 sender/cluster only uses 1 wire. there's no pin to connect the brown/yellow to.

Well, I had to tap one of the 4 wires from the sensor pigtail. I had my head rebuilt with an OBD1 head so I had the provision for the e30 and the OBD2 sensor. Of the 4 wires there are two for cluster temp and two for dme temp signal. It seemed to me the cluster used one of these for ground instead of grounding to the block like the e30 sensor, I left connected in case the circuit didn't ground to the engine. I ran my single wire off the M20 sender to the BR/YW wire that is running to pin 11.... I think it ends there.

Few things i see. Recheck where C101 Pin 7, 12, 14, and 20 go. You have them going to the wrong places on the X20.
Hint: 2 of the wires arent on the X20 theyre on another connector
;)

14 is going to 9, just got that sorted. Throw a brotha a bone on 12 cmon!



IIRC the M52 and S52 harness and DME are the same please correct me if they are different.

[nando]

the cluster doesn't use the brown/yellow wire. that's an E36 cluster. the ground goes through the sensor itself into the block. trust me. you can hook that yellow wire up to a random pin on the C101, but it's not going to do anything. also, sometimes pin 20 is actually +12v, not a ground. that would be bad.

[Mr.SWISS]

the cluster doesn't use the brown/yellow wire. that's an E36 cluster. the ground goes through the sensor itself into the block. trust me. you can hook that yellow wire up to a random pin on the C101, but it's not going to do anything. also, sometimes pin 20 is actually +12v, not a ground. that would be bad.

So I need to tap the single m20 sensor wire to the BR/VI wire on the coolant sensor pigtail?

[nando]

hook up the X20 brown violet to the C101 brown violet. Ignore brown/yellow. that's all you need to do..

[brianao34]

Bump for the best wiring thread I've seen yet. Definitely worth a read

[Mr.SWISS]

Bump for the best wiring thread I've seen yet. Definitely worth a read

My car is legit too, all works as it should, oil level, ABS all that and a bag of papitas. Just need to finish it but that M roady be callin me son! :D

[plain325]

For OBDII swaps, where does the VSS from the cluster go? pin 3 of the x6061? The wiring diagram says it is for "TI-measurement(fuel consumption)". There is also an input through pin 9 of the x20 from the ABS/ASC unit called "speed signal right rear".
From what i can find so far, i should be hooking the VSS up to pin 3 of x6061, just want to make sure. I am surprised i have not found a good OBDII swap diagram yet.

[Mr.SWISS]

For OBDII swaps, where does the VSS from the cluster go? pin 3 of the x6061? The wiring diagram says it is for "TI-measurement(fuel consumption)". There is also an input through pin 9 of the x20 from the ABS/ASC unit called "speed signal right rear".
From what i can find so far, i should be hooking the VSS up to pin 3 of x6061, just want to make sure. I am surprised i have not found a good OBDII swap diagram yet.

Look at my chart, the missing X20 pin you found in the 6031, good job! Now connect that to the road speed signal pin labeled in the chart.

[M3Fresh]

Just wanted to Bump this thread as I feel there is a lot of great info here but I am stommed at the moment.

I am doing a S52 swap into a 85 325es. I am also using the OBD2 harness that came with the motor (belive its an auto trans one, not sure if this will make it harder) and I already did the OBD1 Manifold swap to the motor. The motor and trans (ZF) is all bolted. Pretty much I have all the mechanical stuff already in and made an adapter harness From E30 body (square C101) to X20??(e36 body, not sure if its the right connector) that would then plug into the E36 X20 harness motor side.

Just by looking at different wire/pinout diagrams and some of the stuff on different forums I was able to get this adapter going and I felt pretty confident until I went to start the car Sunday night. Would not start.

Found out I was NOT getting Fuel (the C104 in the glove box is not hooked up)

I am getting spark (even the when the key is in and the ignition is in the on position is still giving me constant spark?? Is this normal?)

Also on the DME side of the wiring harness I have it hooked to a Red label "413" DME. From what I believe I have have the EWS disabled (am able to crank the car over?).

I guess the easy way out is ask for what I need but I like to challenge myself. I have looked into the wiring side for countless hours and am at a loss. I understand the mechanical side of things just fine but all this eletrical/wiring stuff is beyond me...

Any help would be greatly appreciated. Has anyone done what I am trying to do and keep the swap OBD1? by running an OBD2 harness? From what I understand, it should work but I would rather have someone tell me now it doesnt work because I have a space OBD1 harness that I can use and plug it right up?

[328ijunkie]

Again as i mentioned to you. This will NOT ever work. OBD1 ECU connector on left OBD2 ecu connector on right:


You may have fried a number of things in doing this.

[M3Fresh]

At this point what would be the best route? I would have smelled something if I fried anything?

I do have an obd1 harness that I can throw on there?

Edit: harness is off a e36 325i I believe, manual