B5 2.7T to B6 A4 Wiring guide

[blitz2190]

So A quick run down of the after run pump and how I usually hook it up. Using the b6 relays I replace the one that supplies the ecm power with a generic 5 post relay so that when the key is on it powers the ecu, and ll the associated bits. when the key is off it supplies power to another relay, both the coil and supply pole (I use the stock b6 one thats closest to the fron of the ecu box), then using the switched ground from the after run switch, T10n (orange plug) pin 9 brown/red, to trigger the relay, which supplies T10n (orange plug) pin 3 red/yellow with power. When I get home I'll add another diagram to the first page if this is unclear. As for the crash signal you can tap it at a few modules, the easiest being the ccm under the carpet, T12i (black plug) pin 8 lilac/blue. Side note on my 2004 1.8 the wire was on the body plugs and worked, so its hit or miss if its actually been discontinued.

If you do wire the afterrun pump do like tankdeer said and swap the switch for a lower temp one, otherwise it will probably never turn on unless you do a hard pull then immediately turn of the car, which is a big no-no for turbo cars.

[MurkyRivers_A4]

Dont forget Cruise Control :)

[blitz2190]

Dont forget Cruise Control :)

If I can't find that stalk tonight I'll buy another to take pics.

[MurkyRivers_A4]

If I can't find that stalk tonight I'll buy another to take pics.

I have a spare I can send to you if you need it.

[blitz2190]

You have a PM sir.

[AudiA4_20T]

In reference to #2 why do you feel like this pump isn't important? Isn't it's sole purpose to continue circulation of the coolant after the engine is turned off to help cool the turbos? I would think that if the engineers at Audi felt it was important enough to make then it must make a difference on life expectancy of the turbos. I don't know this for sure but I'm just sharing my line of thoughts.

It's generally deleted by the B5 guys with 0 issues, is another spot for coolant leaks, and requires a bunch of extra wiring.

[blitz2190]

It's generally deleted by the B5 guys with 0 issues, is another spot for coolant leaks, and requires a bunch of extra wiring.

Yeah I removed mine, I've always been sure to cool the engine down the last mile or two of any drive. Also if its gotten hot enough for it to turn on when you shut the engine off, its too hot and your cooking the oil that is now sitting in the turbo. There really is no reason it should ever come on if you drive correctly. Audi most likely added this pump because the typical consumer will drive around flooring it to beat the guy next to them, never cool down a car properly or treat it right, so this was a reliability preventive measure.

[Matt_g]

I was hoping you guys would say there's a wire right behind the dash because I really didn't want to have to tap into the CCM or the SRS but if I have to then so be it.

The way you described your wiring is the way I did mine already I just haven't tested it yet. I did already get the lower temp switch due to all of the research I did before attempting this swap. I completely see the logic behind your reasoning on why Audi installed them and I will never do that but I still like the idea of it especially after long drives.

[Julian Aksnes]

Hello! Im currently soldering the 2,7 harness on to the B7 pins, since the terminals are different.
Nice wiring guide!
But I still have like 10-12 wires left from the 2,7 BES engine (manual) thats not on the wiring guide.
Also, my ECU is not getting power. I have used the 30 +12v on the nut
The ground is in place. Suggestions?

just some pictures for attention :D

[blitz2190]

BES? do you mean BEL? also this is only for the APB harness, though the bel is doable its not covered here at all.

EDIT

after looking the BEL and BES should be the same wiring wise, I hadn't seen the different engine code.

[Julian Aksnes]

BES? do you mean BEL? also this is only for the APB harness, though the bel is doable its not covered here at all.

EDIT

after looking the BEL and BES should be the same wiring wise, I hadn't seen the different engine code.

The ARE/BES is similar to the BEL I suppose :)
I guess I have to figure it out by myself then

[blitz2190]

i would talk to clint about making you one. I believe he has done BEL harnesses before, I could but I do not have the time to make a wiring chart let alone a harness at the moment.

[Julian Aksnes]

Im
Having major difficulties with this harness-nightmare
Ive hooked up elsawin on the computer in the neighbour-room.
I have a 2.0 TDI B7, my guess is that the diesel is by far not the same wiring as a petrol.
For example i dont even have a fuel relay..


D23 - Connector (over fuse 229) T10ar(T10n) ORANGE Pin1 red/green T10 BLACK Pin5 red/green t17d RED Pin17 green

whats D23 - connector? The green wire in pin17 goes to a fuse in the sidepanel (15 amp) that says fuel pump on my B7.
And the only place I can see pin3 from ECU mentioned is in the *1 note about the injectors. Whats that have to to with the switched 12v for the pin3?

Some pictures from today

[blitz2190]

Im
Having major difficulties with this harness-nightmare
Ive hooked up elsawin on the computer in the neighbour-room.
I have a 2.0 TDI B7, my guess is that the diesel is by far not the same wiring as a petrol.
For example i dont even have a fuel relay..


D23 - Connector (over fuse 229) T10ar(T10n) ORANGE Pin1 red/green T10 BLACK Pin5 red/green t17d RED Pin17 green

whats D23 - connector? The green wire in pin17 goes to a fuse in the sidepanel (15 amp) that says fuel pump on my B7.
And the only place I can see pin3 from ECU mentioned is in the *1 note about the injectors. Whats that have to to with the switched 12v for the pin3?

Some pictures from today

pin 3 is the switched power on in the 2.7 ecu, if building a jumper harness ignore that comment if not this was how i wired it to be closer to oem. as for the fuse 229 connection that is correct its a power supply from the fuse panel. I know nothing of the diesel or bel/bes engine so things may or may not be the same, you'll either have to ask someone to make you a harness or go through the diagrams and piece it together.

[B6_A4_Kid]

I am in serious need of assistance. I used the wiring guide (which was awesome), but I have 16 connectors left over, that are not included in it. We bought all data DIY, to find the the diagrams, but I cant find the connector views on there it looks like they are just not available. I know for the most part what I am doing with car wiring, but the track style diagrams have me stumped also. The car this is going in is an 05 A4QT, and the donor vehicle was an 00 A6 with the 01E. Really hoping someone on here will help us out. Thanks!

[blitz2190]

I am in serious need of assistance. I used the wiring guide (which was awesome), but I have 16 connectors left over, that are not included in it. We bought all data DIY, to find the the diagrams, but I cant find the connector views on there it looks like they are just not available. I know for the most part what I am doing with car wiring, but the track style diagrams have me stumped also. The car this is going in is an 05 A4QT, and the donor vehicle was an 00 A6 with the 01E. Really hoping someone on here will help us out. Thanks!

which 16? if you followed everything here it will start, theres a few wires you may have to connect like the airbag crash signal to a different source. There are others that I left out like the afterrun pump and switch, this is just a guide an I don't recommend doing it unless you can read and have the diagrams.

[B6_A4_Kid]

The 16 I have left are from T15W Red/yellow, White/Black, Blue, and Red/Gray
T15M Black/Yellow, Green/Black, Gray/Black, Black/Purple, Violet/Blue, And Red/Teal
T10AR Red/Yellow, Red/Brown
T10M Green/Blue and red

I am ASE certified for Auto Electric, just never done anything like this before. Any help is much appreciated.

[blitz2190]

The 16 I have left are from T15W Red/yellow, White/Black, Blue, and Red/Gray
T15M Black/Yellow, Green/Black, Gray/Black, Black/Purple, Violet/Blue, And Red/Teal
T10AR Red/Yellow, Red/Brown
T10M Green/Blue and red

I am ASE certified for Auto Electric, just never done anything like this before. Any help is much appreciated.

t15w is not an ecu plug, there is S4(A6): t15(t15e) or t15m(t15u)

also pin numbers are needed as the wire color is not always right.

[B6_A4_Kid]

Not sure how I am going to get you PIN numbers since the connectors are already removed.


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[blitz2190]

Not sure how I am going to get you PIN numbers since the connectors are already removed.


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they are on the back of the plugs, I would not advise removing a plug whole, I've always done one wire at a time as there are some that are the same color.

[B6_A4_Kid]

Trust me, I know where PIN numbers are on connectors. We got this harness with the connectors removed. So it makes it extremely difficult to figure everything out. The harness was labeled with blue tap wrapped around a pack of wires saying what connector they came out of. Thats it


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[blitz2190]

Trust me, I know where PIN numbers are on connectors. We got this harness with the connectors removed. So it makes it extremely difficult to figure everything out. The harness was labeled with blue tap wrapped around a pack of wires saying what connector they came out of. Thats it


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well assuming then the violet/blue wire that was mistakenly labeled t15m is really from the T3au 3 pin connector attached to t15m thats a crash signal and needs to be tapped into the signal from either the ccm or airbag module itself as you have an 05, the others in that plug that are not connected are not used other than the can signals which you did not list so I'll assume they are connected.

the two on t10ar are for your afterrun pump, one is the switch the other the pump can't remember off hand which is which without my diagrams in front of me.

T10M Green/Blue is not used and I'm hoping the red one is the T10m BLACK pin4 red that needs a constant 12v for the ecu, I would put a fuse inline with this and use a 10amp

as for t15W I have no idea where you got that unless they ment t15 white which would be t15 or t15e in the diagrams, this would makes sense and those would all be your cruise control wires.

again this is all under the assumption that the previous person had a clue and labeled things right. I take no responsibility if these are wrong.

[Julian Aksnes]

Hey blitz! It seems that you got this all figured out, based on your answers in this thread :)
Ive hooked up the harness now (correctly) using your guide and ELSAWIN.
But no matter what, I cant reach the ECU with vagcom. I even sent the ECU to a local tuner to have him check it out, but it was fine.
Every pin have been triple checked via the wiring guide,and even the earth,12v, switched 12v, canbus and K-LINE pins on the ECU are correct.
Does the ECU need anything else to communicate with CANBUS/vagcom? I can communicate with the rest of the car, but not the ECU.
I even tried to remove ECU from the harnes and put 12v, earth and canbus directly to the ECU incase of disturbances in the harness. But no luck here either :(

[B6_A4_Kid]

well assuming then the violet/blue wire that was mistakenly labeled t15m is really from the T3au 3 pin connector attached to t15m thats a crash signal and needs to be tapped into the signal from either the ccm or airbag module itself as you have an 05, the others in that plug that are not connected are not used other than the can signals which you did not list so I'll assume they are connected.

the two on t10ar are for your afterrun pump, one is the switch the other the pump can't remember off hand which is which without my diagrams in front of me.

T10M Green/Blue is not used and I'm hoping the red one is the T10m BLACK pin4 red that needs a constant 12v for the ecu, I would put a fuse inline with this and use a 10amp

as for t15W I have no idea where you got that unless they ment t15 white which would be t15 or t15e in the diagrams, this would makes sense and those would all be your cruise control wires.

again this is all under the assumption that the previous person had a clue and labeled things right. I take no responsibility if these are wrong.

Thanks blitz! We have been busy, but we are looking to work on this some more over the weekend. At this point we are just trying to make the old harness work, it was pretty spanked when we got it. We may just end up picking up a new APB harness and starting over. Thanks again blitz!


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[blitz2190]

Hey blitz! It seems that you got this all figured out, based on your answers in this thread :)
Ive hooked up the harness now (correctly) using your guide and ELSAWIN.
But no matter what, I cant reach the ECU with vagcom. I even sent the ECU to a local tuner to have him check it out, but it was fine.
Every pin have been triple checked via the wiring guide,and even the earth,12v, switched 12v, canbus and K-LINE pins on the ECU are correct.
Does the ECU need anything else to communicate with CANBUS/vagcom? I can communicate with the rest of the car, but not the ECU.
I even tried to remove ECU from the harnes and put 12v, earth and canbus directly to the ECU incase of disturbances in the harness. But no luck here either :(

I dont think this guide will help with the BEL engine, I unfortunaltly do not have the time to go through the diagrams any time soon to look for the differences. but based on that image (may need a better angle to see) it lloks like the pins are not right for your bench harness. should be like the following pulled from nefmoto

[Julian Aksnes]

I found out that my pin21 dont have 12v, since it wasnt mentioned in the wiring guide.
But now I have the ECU up and running, with no fault codes on the engine as well :)
However the engine wont start..
I got spark, fuel in the fuelrail, but the injectors wont open.
I dont know why, but the ECU doesnt seem to ground one of the wires when im trying to start it.
Both hall sensors are okay.
The stribe continues...

[B6_A4_Kid]

Finally got around to screwing with this wiring again, and this what I have left over after following the guide as best I can with the current harness.




At this point we are ready to just buy a new harness and start over, this harness was basically junk so it doesn't owe us anything. But just seeing if anyone has any sort of input here to maybe help us so we don't have to buy a new harness. Thanks in advance!


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[AudiA4_20T]

Nice. I prefer to do the jumper harness but it does have its downsides as well.

[B6_A4_Kid]

Nice. I prefer to do the jumper harness but it does have its downsides as well.

Any advice with where the remaining wires go?

[blitz2190]

Any advice with where the remaining wires go?

not with 100% certainty as they can be different colors, its the pin numbers that never change. but if you have every connection in the original thread it will work (make sure you go through the notes under the chart as well). Like clint said I prefer to do jumpers(haven't done many, most of my wiring is for local people) when I'm sending them to someone but I wire the harness directly like I have in the OP when I'm not mailing them as its easier. A jumper harness requires a bit more knowledge on what and how to power things. you will have a good amount of left over wires for the functions that are no longer needed (b6 chassis reads the canbus for things that those wires did), and the after run pump and switch.

[AudiA4_20T]

agreed, not sure where you pulled those wires from. Makes it hard to recommend things.

[B6_A4_Kid]

I didn't even think about the can bus! That makes this make soooo much more sense now! I'm feeling pretty good about this, just curious on how to power the ECU, and what should I do with all the left over wires?

[blitz2190]

I didn't even think about the can bus! That makes this make soooo much more sense now! I'm feeling pretty good about this, just curious on how to power the ECU, and what should I do with all the left over wires?

covered in the extra notes. most of the extra wires should be taped and covered, you don't want to cut the ones that came from the white plug if you intend to add cruise control. Alternatively I remove the ones I don't use from the harness.

[B6_A4_Kid]

Man you guys are awesome! Really appreciate the help! Just one last thing, I am concerned with the airbag wiring, I really don't want those to deploy on accident. Is that a concern?

[blitz2190]

Man you guys are awesome! Really appreciate the help! Just one last thing, I am concerned with the airbag wiring, I really don't want those to deploy on accident. Is that a concern?

nope, but you won't pass emissions without wiring it up, its not an airbag wire (as in it will deploy them) more so a crash signal from the airbag module to other modules that need the info. The ecu uses this signal to shut down the engine and cut fuel when it detects a crash, some b6's did not have this wire on the body plugs as the signal went to canbus, so you may have to tap the wire on the CCM or airbag moudule itself, they are all the same. I recommend the CCM, its easier to get at and I don't like telling people to mess with the airbag module. FYI I mention emissions because if it has to go on the computer(anything 95 or newer, in emssions states) it will not pass with a CEL light on.

[B6_A4_Kid]

So I am now onto the ECU connector part, and pin 39 and pin 62 are both taken. Do I just need to splice into them? Or will they be a different pin?

[blitz2190]

Do you mean pin 3 on the ecu? 62 needs a fused constant 12v for ecu memory, i used a 10 amp fuse. Pin 3 ties to the injectors in the 2.7 harness near the rubber boot follow the instruction to hook it up.

[B6_A4_Kid]

Do you mean pin 3 on the ecu? 62 needs a fused constant 12v for ecu memory, i used a 10 amp fuse. Pin 3 ties to the injectors in the 2.7 harness near the rubber boot follow the instruction to hook it up.

So do I just splice into the wire already in pin 62?

[Julian Aksnes]

Hello!
im close to having my car back at the road, fully swapped! :)

A couple of questions..
I cant seem to find the T3au connector that fixes the crash signal thingy. Ive looked through ELSAWIN but cant find that 3pin connector anywhere. Is that a bodyplug or a engine connector?
Ive read in this thread that you can hook it up via the ccm. Anyone know which PIN to use there?
Also the brake switch light should be run from the ECU harnes to the left kick panel.. that is the fuse box right? Should it be connected via the brake light fuse?

Picture for attention

[blitz2190]

The kick panel is under the dash against the left wall behind a piece of trim, its so the ecu gets the brake signal mostly used for the cruise control and being a b7 youll have to get the crash signal at either the ccm or the airbag module I would suggest the ccm itd easier to get at and I wouldn't touch the airbag module unless needed