why do i have an X6031 plug on my s52 engine harness

[flyboyx]

i am going through my harnesses and making wiring diagrams but have a few questions. hope someone can help me out.

first of all, the engine is a 2000 s52 from an MZ3 roady. the e30 will be obd2 as i have the complete donor car to rob parts off of.

where the engine harness connects to the body harness by the fuse box, there are two plugs. the standard x20. i have all the wires figured out except a couple.

#8 should be grey, but mine is blank....not a big deal. check engine anyway.
#13 mine is grn/grey. could be o2 sensor/fuel pump relay but different color.
#14 mine is rd/wht. could be ign from dme?
#22 grn/wht. no idea what this is for as most x20's are blank here.



the other big question i have is that next to the x20 on the engine wiring harness, i have a 12 pin x6031 plug. i know that most of the important stuff is in the x20 and it looks like the car might even run without connecting anything to this plug, but...... i really would like to know what i have here. this version of the MZ3 has the guages in the console for oil temp, voltage, etc. could be the wiring for that stuff?

here is how the x6031 is coded:

1 grey
2 grn/blu
3 grn/rd
4 wht/vlt(with ylo dashes)
5 ylo/rd
6 gy/wht
7 brn/blk
8 vlt/grn
9 wht/grn
10 blk/rd
11 blk/brn
12 blk/grn

now, before you tell me to go and get an etm, let me tell you that i have one. i have been through all 382 pages of it. no way i would begin a project like this without it. thats how i know the plug is an x6031. the etm actually sucks balls for this purpose. there isn't a single page that lists the big connectors other than to say what the connector is called and where it is located on the car. no notations for wire position/color/ or function as related to the plug. bastards. all the wire colors labeled in the diagrams are two letter codes for the color name in german. for example, sw is an abreviation for schwartz or black. bastards! any help would be greatly appreciated

[madjurgen]

You have to go through each page of the ETM and scan for 'X6031' and try to find a wire that goes through that connector. Then trace that wire to its origin. Repeat for every occupied port in the connector. Thats the only way to be thorough and make sure that you dont need to hook up that connector. Yes, its a pain in the ass and takes a long time but its the only way to do it imo.

[matt]

I think a lot of that stuff runs to the OBDII port. Check for continuity to the ECU and 20 pin diag ports to see what does what.

The bentley has good diagrams also.

[flyboyx]

You have to go through each page of the ETM and scan for 'X6031' and try to find a wire that goes through that connector. Then trace that wire to its origin. Repeat for every occupied port in the connector. Thats the only way to be thorough and make sure that you dont need to hook up that connector. Yes, its a pain in the ass and takes a long time but its the only way to do it imo.

that was a fantastic idea. i hadn't thought of that one. lucky for me my etm is in pdf format. some of the wires are more useful than others. for example, the asc is about as useful as the tits on a worthog. well, in the event that someone else out there is doing an obd2 swap with a late model s52, here is how they pin out:

1.gy- instrument cluster (i assume it is the chk engine from x20 #8 in other cars)
2.grn/blu- charcoal filter shutoff valve
3.grn/rd- instrument cluster
4.wht/vlt(ylo dashes)- obd2 conector
5.ylo/red- fuel tank pressure sender
6.gry/wht- fuel tank pressure sender
7.brn/blk- fuel tank pressure sender
8.vlt/grn- data link connector
9.wht/grn- asc slip control
10. blk/rd- asc slip control
11. blk/brn- asc slip control
12.blk/grn- asc slip control

[gobuffs]

Dunno if the US MZ3 harness have the same issue as the Euro MZ3 harness do, but there are slight differences between the Euro M3 and the Euro MZ3 harness. The first being that the fuel pump relay on the Euro M3 is on the engine harness while the MZ3 is on the chassis harness. Also the speed signal wire is in a different spot on the MZ3 harness (the chassis side of the X20 is missing the other side of the connector to hook the wire up to).

IOW, you need to review all wires on both sides of the X20 to figure out where things are. It sucks that the electrical issues with these are so varied, so you just need to curl up with the ETM and do the work. I couldn't read the ETM at first but then figured it out. It really isn't that bad, but it is a daunting task at first.