OEM MK4 management wiring => Mk1/2/3 harness install FAQ (Now with added dieselness!)

Hi Jon, thanks for your reply, yes it’s the later type loom. I did remove the d13 wire to carry out the test you suggested. Putting an earth wire to D13 with ignition on did not operate the pump, would this suggest a faulty relay or are there any other wires that I should be checking? Thanks

 

Ok thanks, I’ll give that a go and see what happens. The relay didn’t click at all, the relay I was using had 2 stamped on the top, so I’m guessing that’s incorrect to begin with?

 

Perfect, all working now with the correct relay. Also can I just go ahead and de-pin D15? Thanks for your help

 

Unfortunantly that didnt make any difference. It still wont fire up. Doesnt show any codes.

 

I bought a running spare parts car. Ive tried to swap Coil packs, ecu, ecm. Everything works with the parts car but not the mk2.

Anybody have any ideas?

 

Big thanks Jonny!!! Its working now. The voltage on ign live dropped to Zero when cranking, ive changed the source and viola

 

Hello guys, since I sent my rod through block on my mk3 2E 8v Ill be doing an 1.8T AGU swap from mk1 Octavia. Donor will come in 3 days time so I'm in the process of collecting last bit of info I need. I'm not worried about wiring, as it should be pretty straight forward to convert it to CE2 unless someone before me had some "my friend can do it cheaper" DIY attempts on wiring. Although I have some questions. I've read pretty much whole thread but couldn't seem to find exact answers I need since its quite a big one xD.

1. Regarding coolant temp sensor. Ill be using mk3 4 pin sensor, and I want to know if I can just put it where 1.8T one is originally or do I need the MK4 upper rad hose with sensor fitting anyways ( part number 1J0121087A )?

2. Ill be using 12v VR6 radiator to have coolant hoses on the same side 1.8T radiator has it, and I'm ok with keeping mk3 coolant bottle in the original spot, without moving it to the opposite side, right?

3. I will stick with O2J tranny, so that means Ill be converting to hydro clutch setup. I just need to go on a junkyard run to get TDI pedal box with master cylinder bracket. Ill get the new clutch master cylinder for VR6/16v GTI. What I'm concerned with is, do I need the clutch slave from a mk3 as well or can I keep the 1.8T one?

4. Power steering pump lines from a mk3 should be alright since its a banjo style, which means I get to keep 1.8T PS pump and Its a bolt on fit?

Thank You in advance for your replies, It would mean a lot to get any kind of information so that it all goes in as smooth as possible.

 

1. Cool, mk3 4 pin it is
2. Yeah thats what I thought as well, thats why I will relocate windshield washer reservoir that way I get good amount of space to put cone filter inside fender
3. Oh didnt know it was a fitting issue, so any mk3 should work
4. Okay, ill manage it, shouldnt be a problem since I have gazillion mk2/3 spare parts

Thank you so much for your reply, this thread is a life saver. I will tackle wiring tomorrow, if i get any issues ill be back haha

 

Ok so, didn't have time to do anything last few days so I started today. I just need some confirmation. As I already said, engine is AGU.
These are 3 connectors I have going inside the car ( brown, orange and white ). There are some non existing wires and few wire color differences but I'm using pin numbers as my reference point anyways. Should be alright just need to go through it.


This is the T10a/T14a connector referred to as "connector in engine bay near ECU". For me it was sitting behind the battery on drivers side as shown in picture below. Just need a conformation that this is it.


And this part of the loom going inside/under dash I don't need (well 90% of it), so Ill just cut it there to make it easier for me to separate some wires I need, right?

 

Hi guys, I have an update and a question.

Since my collage is taking most of my time progress is slow, but last night I managed to put the harness in and she fired first try, although O2 isn't connected so she shut off after I released gas pedal.

Regarding the T6/1, I've checked that ECU relay ( I'm using n.30 ) pin 87 is connected to G1/10. Didn't have a wire in this spot so I de-pinned from extra loom and placed it there and fused it with 15A fuse. This is good right?
Also I have noticed that my rev counter isn't working when I fired it, even though I connected it as per thread ( to G1/12 ). What could be the issue since its a mk3?

 

G1/10 doesnt power anything else, and its fused so I sorted that out.
Thanks for the G1/5 earth tip, now its working.
One last thing I hope, my dash battery light is constantly on while car is working, even tho i connected DFM pin to F/03. Dont know what the issue is.