B5 2.7T to B6 A4 Wiring guide

[blitz2190]

Donor body, engine, and harness were all auto. I did add a wire to the body connector to match what your diagram listed (T15e White Pin13 red/green) although the wire I added is black violet, which doesnt matter.

My concern is from the 2.7t harness, basically the receiving side for the T15e White Pin13, having a wire that leads to the ECU for the clutch switch, which I dont think it does. If it does, like you say it does, then I can clip it and splice a new wire and pin it to ECU pin 39.... right?

the ecu plug won't have the wire if its an auto according to elsawin. You'll have to pull the ecu plug apart and solder a wire to the pin(which should be there just no wire) and run that to your clutch switch be it through the body plugs or directly to the switch and the other side of the switch goes to ground.

[MurkyRivers_A4]

the ecu plug won't have the wire if its an auto according to elsawin. You'll have to pull the ecu plug apart and solder a wire to the pin(which should be there just no wire) and run that to your clutch switch be it through the body plugs or directly to the switch and the other side of the switch goes to ground.

That part scares me. I can solder, just not sure how good I would be soldering a wire to a pin....

For the clutch switch ground wire, since my A4 was a manual, that should still be grounded through the body harness, correct?

[blitz2190]

That part scares me. I can solder, just not sure how good I would be soldering a wire to a pin....

For the clutch switch ground wire, since my A4 was a manual, that should still be grounded through the body harness, correct?

yeah the body shouldn't need anything if thats the case(body plugs a4 side should be good as well) also you can pull the pin out to solder it then push it back in. much easier to do i that way. I recommend taping the wires together a little ways back from the plug and securing it at that point(where you taped it) to a table just to keep any other wires from pulling out. also crimp then solder crimp connections are better solder helps make sure its a good connection.

[MurkyRivers_A4]

yeah the body shouldn't need anything if thats the case(body plugs a4 side should be good as well) also you can pull the pin out to solder it then push it back in. much easier to do i that way. I recommend taping the wires together a little ways back from the plug and securing it at that point(where you taped it) to a table just to keep any other wires from pulling out. also crimp then solder crimp connections are better solder helps make sure its a good connection.

Ill definitely take that advice. Thanks again, Alex. Like I said, you've been a tremendous help.

[igz]

I just checked mine as well my donor car is also a 2.7 allroad automatic. The ECU does not have a wire coming from 39... The car in swapping it into is a 3.0 04 avant 6 speed mt. The pin 13 on my t17e white is not red green but rather green grey doesn't matter but should I just pin that wire directly into the ECU via pin 39?

[blitz2190]

Ill definitely take that advice. Thanks again, Alex. Like I said, you've been a tremendous help.

np glad to help

I just checked mine as well my donor car is also a 2.7 allroad automatic. The ECU does not have a wire coming from 39... The car in swapping it into is a 3.0 04 avant 6 speed mt. The pin 13 on my t17e white is not red green but rather green grey doesn't matter but should I just pin that wire directly into the ECU via pin 39?

I thought yours was a b7 based on your pm's, the b7 and b6 have different set ups for wiring.

[igz]

It's a b6 3.0 6speed. I may have pasted the wrong post by mistake I'll have to check. Murkey rivers has been helping me out alot and I've got mostly everything done I believe. Just this issue and verify that the relay next to the ECU is intact the starter interlock relay. My Mitchel diagrams show brown/white wires and so does your chart. But pin 6 on the relay next to my ECU is blue/white

[ADCS]

Mine was an auto ECU and harness as well. For mine, the crimp was present in the harness just no wire terminated to it. Assuming they are all like that it should be simple to pop the crimp out and either crimp it to a wire or solder a wire to the crimp (after removing the crimp from the connector body).

What i did in my case was pull a wire + crimp of the same AWG out of an scrap/extra harness I had and placed​ it into the 2.7 connector in the appropriate location ( I think BEL was pin 39 as well). I did this for a few connections that were missing.

[igz]

awesome. ok ill go see what i can do, can someone verify that the relay next to the ecu is infact the starter interlock relay? just want to double check. mitchell is saying its being the dash... murkywaters and i believe it is.

[blitz2190]

It's a b6 3.0 6speed. I may have pasted the wrong post by mistake I'll have to check. Murkey rivers has been helping me out alot and I've got mostly everything done I believe. Just this issue and verify that the relay next to the ECU is intact the starter interlock relay. My Mitchel diagrams show brown/white wires and so does your chart. But pin 6 on the relay next to my ECU is blue/white

so you retained the interlock relay form the b6 harness? did you also wire the starter wire to it and coming from the body plugs as well? if not the relay will do nothing to stop the starter from working, most don't do this and bypass the relay, but if you intend on keeping the relay I'll give you a hand wiring it when I can look at my diagrams tonight.

awesome. ok ill go see what i can do, can someone verify that the relay next to the ecu is infact the starter interlock relay? just want to double check. mitchell is saying its being the dash...

if you mean for thr b5 s4 its under the dash, for the b6 its next to the ecu.

[igz]

so you retained the interlock relay form the b6 harness? did you also wire the starter wire to it and coming from the body plugs as well? if not the relay will do nothing to stop the starter from working, most don't do this and bypass the relay, but if you intend on keeping the relay I'll give you a hand wiring it when I can look at my diagrams tonight.



if you mean for thr b5 s4 its under the dash, for the b6 its next to the ecu.

I think im doing it a little different that others, i am not making a sperate harness. im simply cutting off the ends of the 2.7 harness and attaching the male ends of my 3.0 harness direct. the ecu, 40 amp fuse and one relay that came with the 2.7 harness are intact, the complete 3.0 harness and wires is gone. my questions is if the relay next to my 2.7 ecu is the one im looking for brown pin 6 to tie into with the wire from my white connector t17e

[blitz2190]

I think im doing it a little different that others, i am not making a sperate harness. im simply cutting off the ends of the 2.7 harness and attaching the male ends of my 3.0 harness direct. the ecu, 40 amp fuse and one relay that came with the 2.7 harness are intact, the complete 3.0 harness and wires is gone. my questions is if the relay next to my 2.7 ecu is the one im looking for brown pin 6 to tie into with the wire from my white connector t17e

if you are referring to J271 that is the ecm power relay and is not needed in this setup (Mine is wired the same way) though you can use it for the relay needed in the additional notes, all the relays/fuses used are part of the b6 side now. the wire color in this thread refers to the interlock relay from the b6 harness. I'll clean up that section to clarify.

[igz]

if you are referring to J271 that is the ecm power relay and is not needed in this setup (Mine is wired the same way) though you can use it for the relay needed in the additional notes, all the relays/fuses used are part of the b6 side now. the wire color in this thread refers to the interlock relay from the b6 harness. I'll clean up that section to clarify.

ok just to clerify and sorry if its a stupid question, i can plug the t15e wire grey/white into the pin 6 of the ecm power relay? this will work? or do i need to go grab the relay from my b6 harness which is removed and re wire that into this 2.7 harness.

[blitz2190]

ok just to clerify and sorry if its a stupid question, i can plug the t15e wire grey/white into the pin 6 of the ecm power relay? this will work? or do i need to go grab the relay from my b6 harness which is removed and re wire that into this 2.7 harness.

if you have already wired it like the chart shows, ignore the interlock wire. also its t17e, t15e is a 2.7 plug(specifically the A6 Just called T15 in s4 diagrams). Then just follow the rest of the diagrams that I have very talentedly(for a 3 year old ) drawn in paint. Updated the additional notes.

[igz]

update: car is firing up and turning off right away, popping a code for immobilizer, i guess even tho its a 01 the allroad had a immobilizer. ill have to wait for my tuned ecu to arrive to see if it will stay running, once again id like to thank everyone that helped. i could not have gotten this far without your help. thank you.

[MurkyRivers_A4]

Mine was an auto ECU and harness as well. For mine, the crimp was present in the harness just no wire terminated to it. Assuming they are all like that it should be simple to pop the crimp out and either crimp it to a wire or solder a wire to the crimp (after removing the crimp from the connector body).

What i did in my case was pull a wire + crimp of the same AWG out of an scrap/extra harness I had and placed​ it into the 2.7 connector in the appropriate location ( I think BEL was pin 39 as well). I did this for a few connections that were missing.

I did exactly what you did. Probably the fastest wiring I've ever done. Took longer to pull the wire from the spare harness than it did to place the wire in the car.

Works perfect, revs drop as they should between shifts, and no error for the clutch switch.

[blitz2190]

I did exactly what you did. Probably the fastest wiring I've ever done. Took longer to pull the wire from the spare harness than it did to place the wire in the car.

Works perfect, revs drop as they should between shifts, and no error for the clutch switch.

glad to hear, now time for upgrades lol.

[MurkyRivers_A4]

glad to hear, now time for upgrades lol.

Right? Lol. So much to do now that everything is working proper. First step is getting a new tune. The GIAC is ok but I know Motoza can and will do better.

[igz]

little update, recieved a 01 s4 ecu, car is running now. still need to figure out a couple of issues with the cluster showing safe but i think im on the right track. :) thanks again guys

[blitz2190]

the cluster showing safe means the key you are using is not paired with the cluster, the ecu will still run as it wont have an immo, but you may get flashing lights from the alarm.

[igz]

its my original key, i can lock and unlock the car with the fob and everything, do you think it might have something to do with me unplugging the cluster a while back, maybe i can just reset it.

[jokh]

from note #1 the post30 is that a 12+ or a ground?

[jokh]

3) the main black/blue injector wire should tie into T10a BROWN Pin1 for a fused connection that turns on with the ecu fuel pump relay signal.

the black/blue and brown pin1 shall they be connected in a relay, that is beeing turned on with the signal from the RED pin 10 red/blue?

[igz]

OK little update, the safe message is gone i disconnected the battery for a while and connected it back, everything is ok. Used the fan diagram you made works perfect. thanks.
i do how ever still have some issues, im having a display on my dash for "press clutch pedal to start car" i believe thats the grey/white wire that i didnt use?...
also my rpm tach isnt working. from what i could figure out from reading its the green.blue wire from the black connector on my b5 harness that goes to pin 37 on the ecu, what wire does that connect to on the b6 side that goes to the cluster? any help would be great.

[blitz2190]

from note #1 the post30 is that a 12+ or a ground?

post 30 is an always hot 12v connection to the battery.

3) the main black/blue injector wire should tie into T10a BROWN Pin1 for a fused connection that turns on with the ecu fuel pump relay signal. As in this wire is hot when the ecu turns on the fuel pump

the black/blue and brown pin1 shall they be connected in a relay, that is beeing turned on with the signal from the RED pin 10 red/blue? Nope if you split the ecu pin 3 wire from the injectors then you just have to wire it as its said, if you did not then you have to change a few things

OK little update, the safe message is gone i disconnected the battery for a while and connected it back, everything is ok. Used the fan diagram you made works perfect. thanks.
i do how ever still have some issues, im having a display on my dash for "press clutch pedal to start car" i believe thats the grey/white wire that i didnt use?...
also my rpm tach isnt working. from what i could figure out from reading its the green.blue wire from the black connector on my b5 harness that goes to pin 37 on the ecu, what wire does that connect to on the b6 side that goes to the cluster? any help would be great.

what ecu are you using, if it came from an A6 it will not work without being flashed to an S4 tune, the m-box works well and passes emissions, as does the A-box with some tricks but I would recommend the m-box tune. To more accurately answer your question, there is no tach wire in the b6 its done through the canbus to the ecu, which is why it needs a S4 tune, the A6 relied on the tach wire.

[Krzysiekvtec]

Gentlemen, I apologize in advance for the translation.
Problem after swap at 2.7 to a4b7
The light constantly shines
Abs 5.7 has the encoding done, the error in the attachment
I ask you for help how to do?

[blitz2190]

looks to me like you cut the wires to the brake pressure sensor that is on the back of the abs pump, and your missing the yaw rate/Acceleration sensor that is behind the head unit in the b6. did you get this when you swapped the 5.7 module in?

[MurkyRivers_A4]

Do we have cruise control options yet, Blitz? I have a 10 hour drive coming up and would like to have that lol.

[Krzysiekvtec]

I had abs 8.0 changed to 5.7. So I have to b6 with this sensor add? The pressure sensor is connected according to the diagram on the first page

[blitz2190]

Do we have cruise control options yet, Blitz? I have a 10 hour drive coming up and would like to have that lol.

I do and I'm going to get a new stalk, because I owe it to someone for donating theirs. I'll have to take pics as its not really the cleanest way to go about it. Basically I removed the pin header and plastic around it from the b6 stalk, removed all the resistors from the stalk board and soldered wires directly to it then ran those wire to the ecu. It works to switch my tunes but I still haven't wired my, clutch switch to see if cruise control actually works.

I had abs 8.0 changed to 5.7. So I have to b6 with this sensor add? The pressure sensor is connected according to the diagram on the first page

you need the g202 yaw rate sensor behind the stereo head unit from the b6, and it needs to be mounted in the same orientation as it was on the b6. Also the wires to the pressure sensor should not have been cut, those in the diagram are just there for reference, the pressure sensor should be on the back side of the abs pump. do you have any pics?

[MurkyRivers_A4]

I do and I'm going to get a new stalk, because I owe it to someone for donating theirs. I'll have to take pics as its not really the cleanest way to go about it. Basically I removed the pin header and plastic around it from the b6 stalk, removed all the resistors from the stalk board and soldered wires directly to it then ran those wire to the ecu. It works to switch my tunes but I still haven't wired my, clutch switch to see if cruise control actually works.

I have an extra stock so definitely looking forward to the pics. This would be the final piece to get everything normal.

[blitz2190]

I have an extra stock so definitely looking forward to the pics. This would be the final piece to get everything normal.

Well that and a trigger for the aux fan for when the a/c condenser is hot. Speaking of which i need one more person to test for when i get the controller made hopefully in the next few weeks, it was already hot a few days here. Currently looking at osh park for the boards but they take like 3 weeks to get.

[MurkyRivers_A4]

Well that and a trigger for the aux fan for when the a/c condenser is hot. Speaking of which i need one more person to test for when i get the controller made hopefully in the next few weeks, it was already hot a few days here. Currently looking at osh park for the boards but they take like 3 weeks to get.

I've just been rolling how it's been with fans running full time. Probably not the best but it's too hot not to have AC and my AC works perfect this way.

Also, I meant extra stalk not stock lol.

[jokh]

so tried to start up the engine after finishing the harness, car wont start.
Checked that ECU gets power and it does, but the ecu does not have any wires at pos. 21-22-23-24, so it looks like ecu is powered from ecu pos 20 and not 21.
Fuel pump and starter works fine, however car does not make spark. The coils get 12V and ground as it should, but when turning the engine the coils gets one small signal, but that is all it gets.

Immoblizer is removed from ECU.

Have some experienced something like this? or any advice

Thanks

[Matt_g]

I'm currently doing my swap using a 2003 3.0 01E, a 2001 Allroad auto engine and harness, and a 2001 M-box. I have a couple of questions.

I don't have a wire on the body side for the crash signal/airbag signal. My diagrams say this wire was being phased out in M.Y. 2003. Has anyone else encountered this and does anyone know of a fix?

I know a lot of people don't use the after run coolant pump but I plan on hooking mine up. I'm pretty sure I've figured it out using a B6 relay from the old harness, I was just wondering why it's not even mentioned.

I've also been trying to figure out the cruise control issue while I was figuring out the wiring. I have 3 extra stalks that I'm willing to sacrifice for the greater good. I've already disassembled one to try and figure out the signals and I would love to discuss thie way you modified yours to make it work.

Thanks in advance for any and all help

[AudiA4_20T]

I'm currently doing my swap using a 2003 3.0 01E, a 2001 Allroad auto engine and harness, and a 2001 M-box. I have a couple of questions.

I don't have a wire on the body side for the crash signal/airbag signal. My diagrams say this wire was being phased out in M.Y. 2003. Has anyone else encountered this and does anyone know of a fix?

I know a lot of people don't use the after run coolant pump but I plan on hooking mine up. I'm pretty sure I've figured it out using a B6 relay from the old harness, I was just wondering why it's not even mentioned.

I've also been trying to figure out the cruise control issue while I was figuring out the wiring. I have 3 extra stalks that I'm willing to sacrifice for the greater good. I've already disassembled one to try and figure out the signals and I would love to discuss thie way you modified yours to make it work.

Thanks in advance for any and all help

1. Crash wire gets hooked up to another wire if it's not on your wiring. I'll check when I'm home
2. It's not mentioned because it's a lot of wiring for nothing.
3. Blitz would have more here.

[Matt_g]

1. Crash wire gets hooked up to another wire if it's not on your wiring. I'll check when I'm home
2. It's not mentioned because it's a lot of wiring for nothing.
3. Blitz would have more here.

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.

[tankdeer]

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.

Yes, that's it's sole purpose. It actually runs the coolant in reverse too. Personally I would opt to keep it if possible

[blitz2190]

On my phone atm so clint will beat me to the first question, as for the after run it can be done but unless you swap the switch its all but usless as its too high temp, the stock one should never come on if you properlycool the car down. Ill post how i wired it for a few people when I'm home.

[tankdeer]

Yes but swapping the temp sensor is easy and well documented.