Help. 1.8t B6 Coil Pack Harness - OEM Replacement.

[iamshayan]

Hey guys,

My coil pack wires are brittle and dying, I ordered a replacement from USPMotorsports

I wanted to make this post to not only draw conclusions to my own questions but also to help others in the future that may come across a similar situation and have the same questions as me.

http://www.uspmotorsports.com/Coil-P...placement.html

I'll start off with the harness I purchased, it come pre-assembled but it seems they use a generic one for all 1.8t motors, be in in an A4 or a Jetta.

USP has a link to a DIY for install on a Mk4 but I think ours may be slightly different. If I'm not mistaken there is one plug on the harness which we do not use.
link found here : http://www.squarewave.com/army/andre...b.97-04-02.pdf

I'm very keen on re-pinning the harness as I feel this provides a better connection than cutting and splicing.
The new harness even comes with numbers attached to each wire so you know which pin to replace in the main connector.

My main issue is. Which plugs are needed, and which ones should lay dormant?

Here is a picture of the harness I got.

I'm sorry I cut it up before I took the picture so the extra wire is laying outside the harness opposed to inside.

The VW DIY says to cut out the "speed sensor" at breakout point A



Then it says to cut wires 2 & 3 from the side B.

ultimately leaving your harness looking like this.



What I am confused about. Is, now what do I do with the big plug and the brown wire.

I have a feeling I have to just cut off the big plug too and the brown wire is ground. can anyone confirm this?

as the plugs I have in the bag are as follows



and then when you reference it to the bentley ewg's it shows 5 wires go into the main loom



I also found this 034 link for reference too,http://www.034motorsport.com/docs/1....structions.pdf

it shows the each coil has a vc ground, 12v power, trigger wire, and other ground (4 wires per plug)...

assuming each coil pack has a shared valve cover ground, constant 12v, switched 12v and other ground with 4 independent
trigger wires. that would explain the wires I am left with.


Its

Wires in the main bag

trigger 103
trigger 102
trigger 94
trigger 95
constant power+ 121

Extra brown - GROUND

Extra plug (purp/black)
Attach (solder) to the old pin 121 you removed & replaced. or other good switched 12v



like this ^

[VCU]

Hey so essentially your saying you dont need the brown wire or the plug? or do you just need to ground the brown wire and cut the plug? im doing mine now and searched for that plug for a good hour haha. and also are you saying that pins 114-121 are all constant power wires (the big ones)? Thanks.

[iamshayan]

Hey so essentially your saying you dont need the brown wire or the plug? or do you just need to ground the brown wire and cut the plug? im doing mine now and searched for that plug for a good hour haha. and also are you saying that pins 114-121 are all constant power wires (the big ones)? Thanks.

you neeeed to ground the Brown wire. Then cut the plug off the Purple and black wire and show it switched 12v+, re-pin the rest of the wires into your ecu connector.


Cut off A - as close to the loom as possible as it will not be used
cut the PLUG off B and show it switched power.

[igo4uga0586]

I know this is an older thread, but is there any full DIY for this?

[igo4uga0586]

probably getting the USP one, its only $70 right now, the 034 looks so much easier, but its much more expensive

[mk4laxer]

Ok so if I buy this harness from usp. I need to ground the brown wire and cut off the other plug and thats it? First time doing this and I don't wanna have to buy another harness. Any specific instructions or diy would be greatly appreciated. Thanks guys!

Sent from my SCH-I605 using Tapatalk 2

[MikTip]

Theres an 034 DIY for their harness....which should be very simular....

[MikTip]

http://www.audizine.com/forum/showth...ht=034+harness

[NyteEscape]

i picked up the USP harness a while back, thinking i might sell it now to pick up the 034 one. don't feel like dealing with the extra work and the 034 just looks cleaner, so i figured i should be willing to spend the money on it.

pm me if anyone wants my USP harness, brand new still in the box.

[daverdfw]

i need this and a Fuel Injector Harness, the connectors are all cracked on it too

[CyberPMG]

The only downside with the 034 wire harness kit is that it's only a partial wire replacement. It doesn't go all the way back to the ECU. I had this and worked fine until one of the wires cracked between the 034 harness kit and the ECU (what was left of the OEM harness). The USP kit will replace the entire ignition wire from the ECU to the ignition coils.

Other thing I would suggest is to go get an ignition wire conduit found on the Mk VI VW GTI/Golf. It's cheap, but adds extra thermal protection (and also cleans up the appearance). You can find the harness conduit over at ECS Tuning.

Available in black: http://www.ecstuning.com/Search/Site...duit/ES281285/

and red: http://www.ecstuning.com/Search/Site...uit/ES1261181/

[customa4]

Other thing I would suggest is to go get an ignition wire conduit found on the Mk VI VW GTI/Golf. It's cheap, but adds extra thermal protection (and also cleans up the appearance). You can find the harness conduit over at ECS Tuning.

Available in black: http://www.ecstuning.com/Search/Site...duit/ES281285/

and red: http://www.ecstuning.com/Search/Site...uit/ES1261181/

That's a damn good idea

[igo4uga0586]

So it is confirmed we do cut off the speed sensor?

Cut the end off the brown wire and ground it?

Cut the big plug off the purple wire and show this switched 12+

Follow the repining instructions exactly as in this bulletin?

http://www.squarewave.com/army/andre...b.97-04-02.pdf

[igo4uga0586]

So it is confirmed we do cut off the speed sensor?

Cut the end off the brown wire and ground it?

Cut the big plug off the purple wire and show this switched 12+

Follow the repining instructions exactly as in this bulletin?

http://www.squarewave.com/army/andre...b.97-04-02.pdf

bump

[igo4uga0586]

So it is confirmed we do cut off the speed sensor?

Cut the end off the brown wire and ground it?

Cut the big plug off the purple wire and show this switched 12+

Follow the repining instructions exactly as in this bulletin?

http://www.squarewave.com/army/andre...b.97-04-02.pdf

Bump once more

[Sundevil84]

I used this harness, and YES I did cut off the speed sensor. I basically just matched up wire to wire and then ran it all the way back up behind the motor. It is a pain in the ass to do, and be ready to blow a fuse if you don't have it connected just right. But I did it over a year and a half ago and have had no problems since (fingers crossed).

[ECS Tuning-Audi]

The only downside with the 034 wire harness kit is that it's only a partial wire replacement. It doesn't go all the way back to the ECU. I had this and worked fine until one of the wires cracked between the 034 harness kit and the ECU (what was left of the OEM harness). The USP kit will replace the entire ignition wire from the ECU to the ignition coils.

Other thing I would suggest is to go get an ignition wire conduit found on the Mk VI VW GTI/Golf. It's cheap, but adds extra thermal protection (and also cleans up the appearance). You can find the harness conduit over at ECS Tuning.

Available in black: http://www.ecstuning.com/Search/Site...duit/ES281285/

and red: http://www.ecstuning.com/Search/Site...uit/ES1261181/

Thanks for the reference and posting the link!

Jason

[Matt Devo]

So it is confirmed we do cut off the speed sensor?

Cut the end off the brown wire and ground it?

Cut the big plug off the purple wire and show this switched 12+

Follow the repining instructions exactly as in this bulletin?

http://www.squarewave.com/army/andre...b.97-04-02.pdf

- remove speed sensor connector at point A
- remove 2 loose wires from point B
- ground brown wire
- cut purple wire w/connector (unused as far as I can tell)
- re-pin 5 wires in ECU connector as per instructions

explanation:
each ignition coil has 4 wires:
(1) switched 12v, shared, runs to ECU pin 121
(2) ground, shared, the loose brown wire
(3) 12v trigger, not shared, ECU pins 94/95/102/103
(4) ground to VC, shared

everything else in the harness can be cut and discarded. I'm not sure why Shayan connected the purple wire to switched +12v, unless there's some funny business going on in the harness that's not visible. If it were me, I'd disassemble the harness to remove any unused wires completely and be able to physically trace everything out

[igo4uga0586]

- remove speed sensor connector at point A
- remove 2 loose wires from point B
- ground brown wire
- cut purple wire w/connector (unused as far as I can tell)
- re-pin 5 wires in ECU connector as per instructions

explanation:
each ignition coil has 4 wires:
(1) switched 12v, shared, runs to ECU pin 121
(2) ground, shared, the loose brown wire
(3) 12v trigger, not shared, ECU pins 94/95/102/103
(4) ground to VC, shared

everything else in the harness can be cut and discarded. I'm not sure why Shayan connected the purple wire to switched +12v, unless there's some funny business going on in the harness that's not visible. If it were me, I'd disassemble the harness to remove any unused wires completely and be able to physically trace everything out

So here is the scoop.

Inside the harness there are two power sources that run into a butt connector (black wire purple stripe) These two power wires (and one of the coil pack wires go in one side, and the other 3 coil pack wires go in the other) so it looks like this

Pin 121.......................=.....=Coil Pack
Another switched power====Coil Pack
Coil Pack.....................=.....=Coil Pack

This is also done with the grounds near the coil packs.

The wire colors did not match up anywhere for me

I first tried to not use the wire that has the plug you have to cut off but the car would not fire up, it would just turn over. I also got P0688

As soon as I added this additional power (I used the old 121 wire) it fired right up.

With a manual transmission, I could have wired the new speed sensor in but I chose not to, and just terminated the two wires in breakout "B"

I grounded the brown wire in breakout "B" directly to the battery, and then repined the remaining wires into the ECU

Its actually pretty easy now that I have done it, I can help anyone who has questions.

















.......Only if we could get a fuel injector harness replacement



PS... I got my red top coil packs for $18.75 from ECS :)

[Elliott]

How are you going to repair that fuel injector wiring? I need to do the same.

[igo4uga0586]

How are you going to repair that fuel injector wiring? I need to do the same.

I don't know anyone who makes a replacement!

[walky_talky20]

Repair wires from the dealer (like 5 bucks per wire, though), or junkyard. It might be best to get the junkyard harness from a car that doesn't have issues with killing those wires. Like a non-turbo Audi/VW, perhaps.

[splash3_11]

Or you can do what I did this weekend and splice this fuel injector harness in.
http://bit.ly/Jzm4hi

[Elliott]

Or you can do what I did this weekend and splice this fuel injector harness in.
http://bit.ly/Jzm4hi

Are you happy with the quality? Smooth install?

[splash3_11]

I am happy with it. They even add the small rubber seals on the individual pins before being inserted in the connector housing...idk if that made sense.....install was straight forward though, trace the wire and splice new one with butt connectors. It fixed an injector cel I had and idle is smooth.

[igo4uga0586]

Can You link us to the exact things you used for the fuel injector harness repair?


Sent from my iPhone using Tapatalk

[splash3_11]

All I bought were the injector pigtails which are good to go. Just need to buy butt connectors and heat shrink. Here's a pic of them if the link above doesn't work. They can be found on EBay by searching a4 ev1 injector connectors. Hope that helps.

[customa4]

The part number for the butt connectors is ncluded in this video along with how to use butt connectors. Click

[iamshayan]

- remove speed sensor connector at point A
- remove 2 loose wires from point B
- ground brown wire
- cut purple wire w/connector (unused as far as I can tell)*******THIS NEEDS SWITCHED +12V****
- re-pin 5 wires in ECU connector as per instructions

explanation:
each ignition coil has 4 wires:
(1) switched 12v, shared, runs to ECU pin 121
(2) ground, shared, the loose brown wire
(3) 12v trigger, not shared, ECU pins 94/95/102/103
(4) ground to VC, shared

everything else in the harness can be cut and discarded. I'm not sure why Shayan connected the purple wire to switched +12v, unless there's some funny business going on in the harness that's not visible. If it were me, I'd disassemble the harness to remove any unused wires completely and be able to physically trace everything out

sorry my post is so confusing, glad you figured it out.

[Menyahs]

After 6 months of looking at the new USP harness I just finally tackled mine. The lack of a full DIY or detailed photos of some steps had kept me a little afraid of starting this. All good now, no misfires and silky smooth idle. Took about 3-4 hrs including a trip to the store for fuses and a couple breaks. For anyone that has concerns similar to what mine were, I took many High-res photos of the process. . . specifically de-pinning the harness and other things that I was never able to find any pictures of. Will post once I have time to do a proper write up of how I did mine.

This was the most helpful thread I found on the subject though

[jinxed]

That's good to know. I was researching this as well & couldn't find much info. Did you run the wires in the main loom or, did you just tie wrap it to the outside of the loom? It's hard to see exactly where the main loom goes once past the valve cover. My wires are brittle so, I don't want to fiddle with the harness to much.

[Menyahs]

That's good to know. I was researching this as well & couldn't find much info. Did you run the wires in the main loom or, did you just tie wrap it to the outside of the loom? It's hard to see exactly where the main loom goes once past the valve cover. My wires are brittle so, I don't want to fiddle with the harness to much.

I had originally started to separate the coil harness out of the main loom which seemed very daunting and one of the reasons I kept delaying. Seems like most people have just cut the old harness and just zip tied the new one along the main harness. . .which is what I did. I did end up tapping into the power and ground from the old harness with the Purple wire from the end of Post #1.

[IMG][/IMG]

[endtitan]

.... I did end up tapping into the power and ground from the old harness with the Purple wire from the end of Post #1.

[IMG][/IMG]

Where exactly did you connect the purple and back wire (one that was connected to unused plug)? And to make sure the brown wire labeled #7 you grounded.

[n7plus1]

What the hell are you guys doing to these harnesses that they need to be replaced?

[Matt Devo]

What the hell are you guys doing to these harnesses that they need to be replaced?

the plastic wire insulation is only good for so many heat cycles

[endtitan]

I just about got my wire harness hooked up just not sure about the where the unused plug (purple/black wire) gets connected or if it does.

[Menyahs]

Where exactly did you connect the purple and back wire (one that was connected to unused plug)? And to make sure the brown wire labeled #7 you grounded.

I connected the Purple wire to the Red/Green 12v source from the old harness, and the brown wire in the new harness to the old Ground connection from the old harness. Even though they were removed from the ECU harness they were both still connected somewhere else in the harness.

Here is the cut old harness that I spliced into [IMG][/IMG]

I ended up wiring in new fuel injector harnesses about a month ago. . . I still have a random misfire on cyl #3. I'm not sure if it's a result of splicing into the old harness that potentially has a short somewhere. I am going to redo the two wires you're asking about at some point to see if that finally fixes my problem. . .if not I'm thinking I have a small vac leak

[endtitan]

Got everything hooked up but no luck, engine didnt turn over. When it did it was just for a few seconds. No fuses blown, not sure what to do next maybe coil packs

[Menyahs]

Got everything hooked up but no luck, engine didnt turn over. When it did it was just for a few seconds. No fuses blown, not sure what to do next maybe coil packs

Hmm. . .It is cranking and just not starting, or not cranking over at all? I wouldn't think that is the coil packs. . .unless they all somehow got fried.

You may have already seen this but here is a link to the little write up on my install http://www.audizine.com/forum/showth...ness+installed

[endtitan]

Shes turning over now, removed relay #30and installed back on not sure if it was loose or the prongs needed to be clean. but still idle rough and the CEL came back on. Going to code check at Autozone see if its the coil packs. Thanks for all the help, im sure I will need more help.