Backstory:
Purchased an E36 318i, M.Y. 1992. Motor (M42) is tired, noisy timing chain rails, low on compression, blah blah blah.
Started stripping the car to become a track car, possibly a NASA GTS car (gonna give it another shot, for those who remember, I tried it with a VW Mk3 GTI, long story, aborted build)
Fast forward to yesterday. Purchased a S52 M3 drivetrain. Everything. Motor, gearbox, engine harness, ecu, diff, axles... Head is bad, so going to pull it and have it rebuilt, injectors rebuilt, ect.
My issue, and yes, I've googled for the last day trying to find this topic:
Trying to find any type of wiring diagram for converting an OBD2 S52 engine harness to work with OBD1 M42 wiring harness. Not concerned with emissions or climate control or immobilizer. Just need to find what will communicate with what to get the engine to run.
Thanks fellas!
R3vlimited.com is the headquarters for DOHC six swaps.
OK, so... you want to connect the M42 car side to the S52 engine harness. You are going to need a wiring diagram but it's no different than mapping it to an E30 except that more stuff should be the same on both sides.
The round firewall connector might even be the same so you can just move the wires around that need it. If it's not, you make a pigtail with the M42 (you have) engine side to an E36 firewall side (you'd need) so you can do all the mapping in-between and have a nice neat connection on both ends at the screw connectors.
There are only three or four wires you need to make it run. The rest are dash signals and so on. If you have a wiring diagram it won't be difficult.
If you dont have all the stuff to make the EWS happy, just get someone to delete the EWS. The whole thing should just plug in.
I just finished swaping an M52 into a 318 with no problems. I did have the donor car so all the EWSII was transfered over.
You should be able to find the diagrams here:
Wedophones
Thanks guys.
Yep. the M42 body harness is the round connector style. I'll have to find a pin out of both and decipher what does what. Was also planning on finding out if I would have to send my S52 ecu off to be bench flashed or have a solder-in chip put in for the EWS bypass
