98 S52 OBD 2 Wire Harness

[Slovik]

Finally got around to starting my S52 swap last week into my 91 318is, The engine I got was from a 98 M3 automatic and has a lot of unnecessary wires. Have any of you seperated the harness or do you just bundle the extra wires together. Also after going through the wiring diagrams a couple of times I came up with following functions on the x20 but would like others to take a look and see if I made some errors and a couple of these I am really unsure of. I will be keeping the car OBD 2 and having TRM disable the EWS and rear sensors etc. I have seen a couple of wire harness conversion charts for OBD 2 S52 but I guess they were for different years as they had a position 14 for road speed or oil level mine has no wire at all at 14.



Color Function
1) Blank -
2) Blank -
3) Grey / Violet ?
4) Black / Blue Compressor Control Relay
5) Black / White ? Pressure Switch (pg 100)
6) Violet / Grey Climate Control
7) Thicker Green Ignition Switch / EWS
8) Red / White (thicker) O2 Sensor 1 & 2 Heater Power
9) Brown / Red Traction Control / ABS
10) Blank -
11) Brown / Yellow Coolant Temperature
12) Brown /Violet Coolant Temperature
13) Green /Violet Fuel Pump Relay
14) Blank -
15) Black / Green Starter Relay
16) White / Yellow Data Link
17) White Violet DME Diagnostic Connection
18) Black / Yellow (thicker) Starter Ignition
19) White / Green Instrument Cluster Diagnostic
20) Black Engine Speed Signal
21) Thinner Green DME - Power
22) Green White (thicker) O2 Sensor 3 & 4 Heater Power
23) Brown / Green Oil Pressure
24) White / Black Fuel Consumption
25) Blue Alternator

I would appreciate any input.

Thanks,

Seth

[M3 euro ltw]

off hand

I'd check 9 and 15.

I spend a lot of time on these harnesses, and off the top of my head, I'm pretty sure that a Brown/Red wire is usually a coolant sensor wire, or oil temperature wire. (vs abs). For oil that may only apply to the Euro or S54 cars since they have oil temp on the cluster.

I thought the Black/Green wire was for the unloading relay. IE the relay that powers down the rest of the car (window switches, radio etc) so that when you try and crank, all the battery power goes to the starter.

could be wrong, but off hand, that is what I saw.

Alex.

[Slovik]

Thanks Alex, I went back through the wedophone wiring diagrams for a 98 M3 again this time documenting the page of the PDF so that others might look back on this when they are doing the same swap (I would imagine the OBD II will eventually become really common) I found the unloader relay at position 21 (Thinner Green Wire) Position 9 I can't find as reading these wiring diagram can be a little hard on the eyes. I know a number of other members here have done this conversion, I was hoping to get some information on how they did their x20 to c101 connections.

Wire Positions By Color on X20 – 98 s52

Color Function Page
1) Blank -
2) Blank -
3) Grey / Violet ?
4) Black / Blue Compressor Control Relay 100
5) Black / White ? Pressure Switch 100 & 271
6) Violet / Grey Climate Control 101 & 269
7) Thicker Green Ignition Switch / EWS
8) Red / White (thicker) O2 Sensor Power 96
9) Brown / Red Traction Control / ABS
10) Blank -
11) Brown / Yellow Coolant Temperature 94 & 218
12) Brown /Violet Coolant Temperature 94 & 218
13) Green /Violet Fuel Pump Relay 96 & 29
14) Blank -
15) Black / Green Starter Relay 120
16) White / Yellow Data Link 81
17) White Violet DME Diagnostic Connection 79
18) Black / Yellow (thicker) Starter Ignition 119
19) White / Green Instrument Cluster Diagnostic 84
20) Black Engine Speed Signal 99 & 52
21) Thinner Green Unloader Relay 94
22) Green White (thicker) O2 Sensor Heater Power
23) Brown / Green Oil Pressure 216
24) White / Black Fuel Consumption OBC 221 & 286
25) Blue Alternator 117 & 83

Thanks,

Seth

[M3 euro ltw]

wires

OK, so I was a bit helpful on the unloader relay wire...

Go back to your ETM for Pin 9, and search carefully in the cluster section of the ETM, it may be there.

If you really think its ABS for some reason, then look in that section, but I don't think so.

ETMs can be challenging.

There are some ways to convert the pdf's into a better or different version of the file where you can do a search for the german abbreviation of the wire color, and find every reference to it. Tedious, but effective if you're really stuck hard on an X20 ID problem.

I'm not an expert on this conversion, but its out there, someone may be able to help you.

[Link]

Thread bump, about to start this same swap, 98 s52 into a 91 e30. Curious if anyone can confirm this:

Wire Positions By Color on X20 – 98 s52

Color Function Page
1) Blank -
2) Blank -
3) Grey / Violet ?
4) Black / Blue Compressor Control Relay 100
5) Black / White ? Pressure Switch 100 & 271
6) Violet / Grey Climate Control 101 & 269
7) Thicker Green Ignition Switch / EWS
Red / White (thicker) O2 Sensor Power 96
9) Brown / Red Traction Control / ABS
10) Blank -
11) Brown / Yellow Coolant Temperature 94 & 218
12) Brown /Violet Coolant Temperature 94 & 218
13) Green /Violet Fuel Pump Relay 96 & 29
14) Blank -
15) Black / Green Starter Relay 120
16) White / Yellow Data Link 81
17) White Violet DME Diagnostic Connection 79
1 Black / Yellow (thicker) Starter Ignition 119
19) White / Green Instrument Cluster Diagnostic 84
20) Black Engine Speed Signal 99 & 52
21) Thinner Green Unloader Relay 94
22) Green White (thicker) O2 Sensor Heater Power
23) Brown / Green Oil Pressure 216
24) White / Black Fuel Consumption OBC 221 & 286
25) Blue Alternator 117 & 83

[luckysnafu]

Link - I can confirm most of your pins match the ones I used for my 96 m52 except for X20 pin 22. On my harness the wire color for pin 22 is green/white and my research shows it has something to do with the diagnostic connector (mine is connected to C101 pin 6). If you have verified your info through wiring diagrams for your year and engine then I would disregard my conflict.

[Link]

So I am trying to confirm all the pin outs using the wedophones.com EMPd but am only finding c101 8 times, there are only a few pages of wire code charts. What am I not understanding? Can someone clear this up.

[Link]

Are there any threads that show how to make your own wire harness from x20 to c101 other than this one http://www.r3vlimited.com/board/showthread.php?t=147862

[36brua]

burn down to post 55

http://www.r3vlimited.com/board/showthread.php?t=134232&page=4