OEM / Usp Motorsports Coil Harness - Installed [pictures]

[Menyahs]

Bought this a few months back http://www.uspmotorsports.com/Coil-P...placement.html

Like many others I have long been plagued by random misfires. Mostly on Cyl #3 and sometimes #4. After Much searching It seems that there hasn't been any detailed write ups on how to install the harness in our cars. I finally got around to installing the harness in my car today after 6 months of procrastination, mostly because was afraid of messing something up. I also made sure all the "easy" things had been done first (i.e. spark plugs, FSI coils, Breather/Vac lines) However, since none of those completely solved the misfires it was on to everyone's favourite . . . wiring

Also I am posting this for the sake of posterity in hopes that it will help future AZ'ers like myself that are a little nervous about tackling this. This is the way I got it done, but you know how it goes. . .Work at your own risk as I can not assume responsibility for any problems but this is the way that it did work for me.

This is the most helpful thread I found on here. I modified the harness and removed the speed sensor wires by following these instructions. http://www.audizine.com/forum/showth...EM-Replacement

USP Motorsports references this technical bulletin from VW but it still doesn't provide a very detailed explaination for someone less experienced with wiring IMHO http://www.squarewave.com/army/andre...b.97-04-02.pdf


Here is the reason why this is absolutetly necessary if you're having issues too. All the wires were hard as a rock, and along with the plastic connectors basically crumbled when I tried to move them at all.
[IMG][/IMG]

Step 1: Disconnect (-) Negative from battery

Step 2: Remove ECU
I used the APR instructions. http://www.goapr.com/support/ecu_a4_b6.pdf
*Note I had to cut through almost the entire head on the security screws to be able to get the damn things out.

Step 3: Disconnect Old wires & Install new wires into the ECU connector

Once you have the purple locks removed from the connector you should be able to (gently) pull out the white and black plastic inserts in which you'll find the 4 trigger wires 102, 103, 94, 95.
[IMG][/IMG]

The number on the new trigger wires on the new harness match up to the corresponding pin number from the ECU. It's a little tedious but the ecu is labeled so just take your time and match them up. I did them one wire at a time and labeled the old wires with masking tape as they were too faded to tell them apart.


[IMG][/IMG]

You'll also need to depin #121, and install the new one.

[IMG][/IMG]

I used the $13 Lisle tool from O'reilly's and had no problems de-pinning. http://www.oreillyauto.com/site/c/de...0221&ppt=C0335

Step 4: Unplug, Remove Old Harness

***Make sure you're ready at this point as I just cut the old wires. . .which is the point of no return if yours are as fried as mine were.
[IMG][/IMG]

Step 5: Hook up 2 remaing wires from new harness 12v+, and Ground(-)
This was kind of confusing to me with the way the harness is laid out why the Purple wire need to see 12v when it's connected to pin #121 on the ecu. But I did veryify, the car wouldn't start with them disconnected. [IMG][/IMG]

I tested the wires from the old harness with my test light and they still had good + and good ground so I just picked two and soldered to the new harness.
[IMG][/IMG]

Here it is after heat shrink and getting taped up. Not the prettiest install but it works. I may go back and clean it up in the future.
[IMG][/IMG]

Step 6: Clean up any remaing wires from old harness
Once again I didn't make this a clean as I could have. I just used heat shrink on all the ends of the wires and then taped them individually, then all together. The previous photo shows the terminated wires to the coil packs all taped up. Pictures below was in process of wrapping up the old trigger wires.
[IMG][/IMG]

Step 7: Double Check & Re-assembly
At this point just make sure you didn't miss anything and re-assemble.
[IMG][/IMG]


This is my first attempt at a full write up or DIY, so I'm sure I have left something out. Once again my goal is to provide a greater level of comfort in doing this work for anyone like myself that might be a little intimidated by this type of job. Apologies for being a bit verbose. . .Hope it helps somone.

Wrench on my friends

[Elliott]

Nice writeup! This is on my list along with wiring for the injectors.

[Menyahs]

Thank You. Injector harness is on my list as well. I'm about to order Stage 1 tune from Motoza but had to make sure everything was running well before turning up the boost

[MikeWire]

Great DIY! Should be stickied in the DIY section.

[daverdfw]

great write up, i just installed new Fuel Injector Pigtail for my 550cc injectors which use an EV14 connector, my old wiring was exposed. the pink tubing is heatshrink that I used after I soldered the cable together



I am about to get some flexible tubing to cover over it and hopefully protect it.

[Menyahs]

great write up, i just installed new Fuel Injector Pigtail for my 550cc injectors which use an EV14 connector, my old wiring was exposed. the pink tubing is heatshrink that I used after I soldered the cable together



I am about to get some flexible tubing to cover over it and hopefully protect it.

Did you do the coil harness as well? Lol in typical fashion my test drive after completing this job was perfect, but no sooner than I had the car completely loaded up to head back to FL Friday morning my CEL came back. Still missing on Cyl #3. Looks like I'll be running new wires to the two that I had tapped into the old harness. Then will be on to fuel injector wiring, and if it still persists I'll swap injector #3 for one of others to see if it follows it.

If that doesn't fix it I fear I must be low on compression for #3, but they said good compression after I had to get my head machined last year after some major warpage. The tech did mention the injectors may have gotten fried too when it overheated . . . (water pump failure on the interstate in BFE).


Also, on a side note about wiring. . . . Just installed my new E Codes today and the wiring inside the headlight housings was in similar shape to my old coil harness.

[daverdfw]

Havent done the Coil harness yet, I was about to order the harness you got from ECS for $65 and the plastic cover that has been referenced a few times. Today I went and got some high temp electrical tape, and wrapped the wires seen in the pic. And then zip tied them to the Fuel line to keep them away from the engine and hopefully from melting. What i did was just cut the orig wires about an inch from where they come out of the main loom. you can see it in the pic. Then I soldered the new wire and shrink wrapped the ends. Hoping this holds up for a while.

[daverdfw]

Also have you tired swapping the coil packs around and see if the misfire follows? Coil packs usually go out on these cars quite a lot, especially if you have old ones.

[Menyahs]

Also have you tired swapping the coil packs around and see if the misfire follows? Coil packs usually go out on these cars quite a lot, especially if you have old ones.

Yes, I had the Hitachi E bolt down coils and I moved a couple around and was still always missing on #3 and occasionally #4. Just installed the Red top TSI coils last month. Spark plugs are brand new too. Seems like any missing on cyl #4 stopped after the new harness but #3 is still having some misfire issues. . . according to my 5 min VAG COM session.

There is some seepage going on around the #3 injector seat so I've probably got an issue of some kind there. Back to work this morning though so won't get to that till weekend at the earliest. Once I finally get it resolved I'll post what I find. With the age of our cars seems like these misfire and wiring issues are getting pretty common

[daverdfw]

I had a misfire the other day and it was because the coil was popping out just a little bit. SO i bought some ECS hold-downs. and now my idle is smoother too. Make sure you push them down really well and see if that helps.

[texasboy21]

I had a misfire the other day and it was because the coil was popping out just a little bit. SO i bought some ECS hold-downs. and now my idle is smoother too. Make sure you push them down really well and see if that helps.

The coils should not pop up if they are properly torqued down. Take that coil off and snug of the spark plug.

[daverdfw]

I have the 2.0 coils that dont sit flush with the valve cover

[texasboy21]

I have the 2.0 coils that dont sit flush with the valve cover

The coil should not pop up at all - tighten the sparkplug.

[Menyahs]

I will definitely check to make sure the plug is torqued down properly. . .Thanks for the tip. Would be awesome if that was it. . .CEL =

I didn't buy the adapters for the coil packs and haven't had any issues with them popping up. Everything I read said they were weren't really needed.

[daverdfw]

I replaced my plugs and re-torqued. Need to do coil harness soon. Fuel injector harness i repaired seems to be holding up well.

[evo_ski]

I am going to be doing this install this week. A little confused on step 5. What wires on the car did you hook the brown and purple wires to, and where did you tap into them?

Thanks!

[GuyFawkes]

I am going to be doing this install this week. A little confused on step 5. What wires on the car did you hook the brown and purple wires to, and where did you tap into them?

Thanks!

bump

[texasboy21]

I am going to be doing this install this week. A little confused on step 5. What wires on the car did you hook the brown and purple wires to, and where did you tap into them?

Thanks!

In the thread below, it says to cut off and ground the speed sensor wire, and tap the switched 12V to the old 121 wire. Post 20.

http://www.audizine.com/forum/showth...EM-Replacement

[daverdfw]

Tried doing this job today, stuck on getting the damn ECU bolts out. Have done the dremel method but the screws dont budge! Going to try using a heat gun to head the glue on the screws to see if that helps. u

[GuyFawkes]

In the thread below, it says to cut off and ground the speed sensor wire, and tap the switched 12V to the old 121 wire. Post 20.

http://www.audizine.com/forum/showth...EM-Replacement

Thanks for the reply. Finally got to try and install it today. Got everything repinned and wired up. Tried to duck tape the purple to red wire for the 12+ and ground to a random bolt, for a test. Turns over but doesn't fire up ;/ Going to check the fusses tomorrow, try doing a better job at connecting purple to red, check for spark, and moving the ground around.

[texasboy21]

Thanks for the reply. Finally got to try and install it today. Got everything repinned and wired up. Tried to duck tape the purple to red wire for the 12+ and ground to a random bolt, for a test. Turns over but doesn't fire up ;/ Going to check the fusses tomorrow, try doing a better job at connecting purple to red, check for spark, and moving the ground around.

You connected them with duct tape?

[daverdfw]

Thanks for the reply. Finally got to try and install it today. Got everything repinned and wired up. Tried to duck tape the purple to red wire for the 12+ and ground to a random bolt, for a test. Turns over but doesn't fire up ;/ Going to check the fusses tomorrow, try doing a better job at connecting purple to red, check for spark, and moving the ground around.

I had to run the ground back to the valve cover ground or I got errors in VCDS and CEL , the ECU thought the circuit to all 4 coil packs was open. Just get a ring connector and some wire and run it back to the Valve cover.

[GuyFawkes]

You connected them with duct tape?

I mean electrical tape haha, sorry it was a long day yesterday. I just didn't want to solder before seeing it work.

I had to run the ground back to the valve cover ground or I got errors in VCDS and CEL , the ECU thought the circuit to all 4 coil packs was open. Just get a ring connector and some wire and run it back to the Valve cover.

Interesting ok ill try that.

[daverdfw]

I mean electrical tape haha, sorry it was a long day yesterday. I just didn't want to solder before seeing it work.



Interesting ok ill try that.

this is the error I got alone with a CEL



As soon as I ran that brown wire from the harness to the Valvecover ground with the other ground wire, errors gone.

The car ran fine when I ran it to another ground or even the - battery terminal, it only went away when I ran it to the VC

[GuyFawkes]

looks like i don't have a spark. Was assuming it was the messed up harness but now starting to suspect one of the relays in the box. (it was flooded a lil while ago i dried them out and cleaned with electric cleaner and it worked for a while but i guess might need to replace.

[texasboy21]

I mean electrical tape haha, sorry it was a long day yesterday. I just didn't want to solder before seeing it work.

Dont use solder, Audi recommends butt connectors.

[daverdfw]

Dont use solder, Audi recommends butt connectors.

I have soldered my Fuel Injector wires and Coil, hasnt caused an issue, wonder why they recommend against it?

[Spike00513]

I have soldered my Fuel Injector wires and Coil, hasnt caused an issue, wonder why they recommend against it?

Because it can change wiring resistance and deteriorate. When faced with the constant shaking of an engine, or bending of wire, solder can break. A properly crimped connection will not.

[Maiky]

hey mate what model 034 crank case breather hose kit do you have ????

[Plaggy22]

Nice write up. I already connected the main pins but not the purple wire and the brown wire. I saw a lot of different DIY which is confusing. Can u clarify this please? Cheers

[daverdfw]

Nice write up. I already connected the main pins but not the purple wire and the brown wire. I saw a lot of different DIY which is confusing. Can u clarify this please? Cheers

Purple wire on mine I went to the old 121 reg/green wire, and the brown I ran back to the valve cover ground with a ring connector.

[A4_newb2006]

Thank you, this is an excellent write up. I am attempting to do the ignition harness on my 2006 Audi A4. I did not know the longer harness was less expensive. I wish I would have found this thread before buying. Did you have to reset any codes after? I am disconnecting the battery like you mention in the instructions.