# B6 A4 TDI Swap questions.



## dorkage (Jul 7, 2009)

I've been looking for info on this subject and I haven't found too much. I found one guy on TDIClub that did a TDI-M swap, but that pretty much by passed the ECU. I just want to know if the cluster from a B6 would talk to the ECU from let's say a MK4 ALH. I'm not too worried about getting the unit in there, everything should bolt up, I just want to know if it would be able to run while retaining most stock features like the alarm and ASR and such. I'd rather not import a bunch of parts from Europe, but I would like to have a Avant with quattro that gets 50MPG.


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## dorkage (Jul 7, 2009)

MikkiJayne said:


> I've just put a TDI in my C5 A6 and ran in to much the same issues that you will do. There are a few things you need to consider with this swap that you might not have thought of.
> 
> Longitudinal and transverse blocks are different. The transverse block does not have the bosses for the longitudinal motor mounts, and in fact doesn't really even have anything to mount fabricated mounts to either. You will need to make custom mounts for it which is doable but fiddly. The longitudinal block is actually a lot stronger than the transverse one too, with extra webbing around the sump flange. The transverse block doesn't fit the bellhousing brace that the longitudinal one uses, and also doesn't have the mounts for the front snubber. It will bolt to the tranny, but nothing else.
> 
> ...


This I am not worried about at all to be honest. These are things that my brother and I can take with some machining or fabricating. I planing on using the 1.8t accessories and the 1.8t flywheel starter and clutch at the beginning. I've read that if I start with a A4 with a 1.8T I just have to get the motor mounts on the motor and that the block should have provisions for it, just not bored out.


> As far as the electronics go, you will need an ECU with CAN Bus and the same specs as your car, otherwise the ASR / ABS will not function properly, and the aircon & airbag ECUs will get a bit narked too. My A6 is Quattro with ESP so I had to track down a TDI ECU from a Passat 4motion with ESP so it would code up properly. That had to come from Germany in the end, and tbh I'm still having coding issues with it but hopefully a trip to the Dealer to see their VAS 5051 will sort that.
> 
> Airbags you should be able to code to a CAN ECU but you will need a 5051 for it as VAG-COM can't do it afaik. The AC controller in the C5 can be coded to suit the compressor on the TDI, so possibly the B6 can too. If its a 1.8T it might be the same though, especially if you keep the same compressor (ie make a bracket to fit it).
> 
> ...


 There is my major worry. 

I think that the ABS and EDL will work regardless, not so sure about the ASR though. I swapped a ASR ABS pump into my 2.slow and got the EDL traction control, but no throttle cut (it's drive by cable). I've also swapped the same pump into my boyfriends 99.5 TDI and it got both the EDL and the ASR since the pump communicates to the ECU via canbus. If I lose ESP, that's not a huge deal, I don't have it on any of my cars and don't really care.

My biggest issue it just getting that ECU to play with that cluster. I'm confident that if I can get the ECU coded to the cluster then it should be cake to get the rest down. I'm a freaking Electrical Engineering Computer Control Technician, so I should handle the wiring, or else my teachers might take away my diploma. 

If it's as simple as splicing the wiring harness together and coding the immobilizer, then this would be a walk in the park for me.

I'll look into this more during the weekend. I hope I can turn this into a reality.


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## dorkage (Jul 7, 2009)

Also, I haven't ruled out using a Passat TDI from a B5. I'm just thinking for what I have within easy reach.


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## dorkage (Jul 7, 2009)

MikkiJayne said:


> Immo wise, highly unlikely. The mk4 is immo 1, possibly 2. The B6 is immo 3, which won't talk to 2. I would expect you will need an immo defeat for this if you use a mk4 donor.


But I can swap a GLI Immo3 cluster into my 2001 VR6 with some coding with vagtacho or whatever it's call, so why wouldn't a similar thing be possible with the B6 and a older ECU? 

It's still in the theoretical stage since I don't have the car or motor yet.


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## Demon Diesel (Aug 30, 2002)

Hope you don't mind me joining the thread but i have very similar questions...

I'm hoping to do an ALH (ideally) swap into an A4 Avant B7 (2005.5-2008). 
I'm still confused on the B6/B7 thing. I know the B7 is a "facelifted" B6 but it should like many of the elevtronics are different too. I know the B7s has a 2.0T instead of the 1.8T and it uses a slightly higher ratio 6spd manual (which is good). 

I want to try and stick with the ALH for a few reasons:
1) I have a complete spare engine already, 
2) I know the ALHs best
3) They are readily avaliable
4) The seem to get the beast MPG
5) Seems to have the most mods avaliable (HP increase)

I'm in the same boat. Electrical is my background so i'm not worried about the "wiring" more the communications and what works and doesn't work. I can also "FAB" mounts but i really don't want to!

What i was planning on doing was picking up a used cluster from an A4 B7 and simply connecting it up to my ALH and see if i can get them to "talk". I'm sort of not worried about the IMMO because my ALH is immo 3 (They came in IMMO, 1, 2, or 3) and i can do a delete on it. What concerns me is that i'm hearing the the B7 is IMMO 4 and uses TP2.0 where as the ALH is IMMO 3 and TP1.6... This leads me to believe that they will likely NOT talk. 

If i could get my hands on a A4 cluster connector with likw 6 inches of wire, i could try it out on my bench.


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## dorkage (Jul 7, 2009)

I saw this on Audizine


> The 2000-2003 VW TDI engine is a direct fit for a B6 1.8T A4. The block is almost identical (actually, the block is used by people making 2.1-2.2L 20V, and the crank is used to make 2.0-2.1L 20v) so it bolts right in. The older TDI block is a direct replacement for early B5 A4. All of the accessories from a 1.8T bolt right up as well, and any 1.8T A4 clutch/flywheel bolts right up. Just like other swaps, it's the electrical system that needs the most attention.


I might be able to get a smashed B6 A4 with a CVT and am considering it just to tinker around to see if they cluster would communicate with the TDI ECU. I have a early MK4 TDI ECU in my room right now that my friend gave me from his parts car, not sure if this would work. It is either no immobilizer or Immo2 (the key didn't have a slash through the W which is suppose to mean Immo2 or something to that affect). Would it not be possible to adapt this ECU to the B6 cluster, similar to adapting a GLI cluster to a earlier Immo2 MK4? If not, would it talk to MK4 ALH Immo3 ECU(another friend might have one of these)? Just grab the SKC with vag-tacho and swap with VAGCOM?


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## Gonzzz (Apr 27, 2010)

MikkiJayne said:


> Immo wise, highly unlikely. The mk4 is immo 1, possibly 2. The B6 is immo 3, which won't talk to 2. I would expect you will need an immo defeat for this if you use a mk4 donor..


 Wrong. NA spec MK4's are either no immo (99.5) or immo 2 or immo 3.

An immo 3 cluster *should* always be able to talk to an immo 2 ECU, but not the other way around


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## dorkage (Jul 7, 2009)

I've inquired about the smashed A4 with a blown motor. If the price is right and it's partout-able, then I might scoop it up. I'm on the trail for a Mk4 TDI ECU with Immo3, but I still have the spare one. Can someone tell if it has Immo by the part number?


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## Gonzzz (Apr 27, 2010)

dorkage said:


> I've inquired about the smashed A4 with a blown motor. If the price is right and it's partout-able, then I might scoop it up. I'm on the trail for a Mk4 TDI ECU with Immo3, but I still have the spare one. Can someone tell if it has Immo by the part number?


 I can tell you if you tell me what year it is or if you can hook it up to VCDS


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## dorkage (Jul 7, 2009)

DJ Gonzo said:


> I can tell you if you tell me what year it is or if you can hook it up to VCDS


It's sitting in my bedroom, it was either 2000 or 99.5. I have the keyfob from it still. But the rest of the car is gone. Can it be hooked up to any mk4 and scanned?


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## Demon Diesel (Aug 30, 2002)

038 906 012 CP Should be IMMO 2
038 906 012 FD Is IMMO 3

I'm not sure of any others right now. Don't worry about the IMMO delete part as thats really easy. If you're having troubles just let me know and i can help you out or just send me your ECU and i'll do the delete (just pay for the shipping).

Let me know if you get any of the ALH ECUs going with the B6 platform. I was thinking of using a B6 cluster with the B7 platform just to make the swap easier but i've heard that the B6 cluster in a B7 causes problems with the HVAC system where it works with the car not running but as soon as you start it up it totaly shuts down ("OFF"). 

My biggest question is will the ESP work??? If that does i would imagine the traction control (ASR) will also.
If you need any wiring info for the ALH, let me know as i have the Bentley and am pretty good at reading the schematics for the car.




dorkage said:


> I've inquired about the smashed A4 with a blown motor. If the price is right and it's partout-able, then I might scoop it up. I'm on the trail for a Mk4 TDI ECU with Immo3, but I still have the spare one. Can someone tell if it has Immo by the part number?


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## dorkage (Jul 7, 2009)

Demon Diesel said:


> My biggest question is will the ESP work??? If that does i would imagine the traction control (ASR) will also.
> If you need any wiring info for the ALH, let me know as i have the Bentley and am pretty good at reading the schematics for the car.


I don't see why it wouldn't. I've swapped a ASR ABS pump into my boyfriend's 99.5 ALH Jetta and it then gained both EDL and ASR, so the ECU receives the command to throttle from the ABS. ESP just adds stability to the package and as far as I know it's fairly independent of the main ECU. I'm not worried about ESP, I have never had a car with it.

I do believe my spare ECU is Immo2, since the keyfob has a W on it like my VR6, where as the boyfriend's 99.5 has a W with a line through it. Should be adaptable provided the pinout to the car is the same. I'll find out about that smashed A4 tomorrow (I hope).


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## dorkage (Jul 7, 2009)

Two questions, I was looking in my Bentley manual last night and it seemed the wiring might have changed slightly on the engine harness every year or so. Is this the case or do I just suck at reading the Bentley? Still no word on the A4, but I got my MK4 Bentley, a VAGCom cable coming. Should I also consider getting a VAGTacho cable?


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## dorkage (Jul 7, 2009)

Well, I got a motor:


















I have the complete harness and ECU as well. Now to figure out if this will play with a B6 or B5. 
Anyone have body harness pinouts for B5 or B6? I've expanded my search seeing how cheap some B5s are.


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## Demon Diesel (Aug 30, 2002)

dorkage said:


> Two questions, I was looking in my Bentley manual last night and it seemed the wiring might have changed slightly on the engine harness every year or so. Is this the case or do I just suck at reading the Bentley? Still no word on the A4, but I got my MK4 Bentley, a VAGCom cable coming. Should I also consider getting a VAGTacho cable?



No you are right... They did change it up a little but if you grabbed everything from the same car you should be ok. I know that the glow plug system is different for


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## dorkage (Jul 7, 2009)

I don't have the money to buy a B6 right now, so the TDI is going into my 1999.5 Golf GL. Should be a much easier swap. I have a complete harness from the late 2000 TDI and I hope I don't have to swap the whole body harness.


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## Demon Diesel (Aug 30, 2002)

dorkage said:


> I don't have the money to buy a B6 right now, so the TDI is going into my 1999.5 Golf GL. Should be a much easier swap. I have a complete harness from the late 2000 TDI and I hope I don't have to swap the whole body harness.


You should be ok just swapping the engine bay harnesses. I know someone that has done a VR6 to 1.8T swap and thats all he needed. 

Good luck!


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## dorkage (Jul 7, 2009)

Demon Diesel said:


> You should be ok just swapping the engine bay harnesses. I know someone that has done a VR6 to 1.8T swap and thats all he needed.
> 
> Good luck!


I'm more worried about the extra things like the Glow plug relay, pedals, and putting the Immobilizer into the 99.5. If I have to swap everything I will, but I can't see the 4door power everything going easily into the 2door power nothing.

Or can you just do a Immo delete and I just swap the pedals and relays in?


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## Demon Diesel (Aug 30, 2002)

dorkage said:


> I'm more worried about the extra things like the Glow plug relay, pedals, and putting the Immobilizer into the 99.5. If I have to swap everything I will, but I can't see the 4door power everything going easily into the 2door power nothing.
> 
> Or can you just do a Immo delete and I just swap the pedals and relays in?


If you have the complete engine harness, it comes with the glow plug relay. Most of the interiour options make no difference in the engine harness. especially that you have a 2000 engine/harness/ecu going into a 1999.5. You will likely be able to get the Immobilizer going too. If not let me know. You can send me your ECU and i can disable it for you. Not an issue. The more chalanging things are havin all the other parts... Tranny, downpipe, engine accessories....

Post pictures when you get the swap started.


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## dorkage (Jul 7, 2009)

Demon Diesel said:


> If you have the complete engine harness, it comes with the glow plug relay. Most of the interiour options make no difference in the engine harness. especially that you have a 2000 engine/harness/ecu going into a 1999.5. You will likely be able to get the Immobilizer going too. If not let me know. You can send me your ECU and i can disable it for you. Not an issue. The more chalanging things are havin all the other parts... Tranny, downpipe, engine accessories....
> 
> Post pictures when you get the swap started.


Oh I'll have to look at that harness again to see the glow plug relays and such. Swapping the pedals is one other thing I'll have to look into since the 2.slow for that year was throttle cable. I got a single mass flywheel and I just need the VR6 clutch kit, timing belt kit and rebuild the blown up turbo since I had to give up the good one I had because I blew up my significant others TDI at a autocross.










It went through 3 liters of oil in about 30 seconds.


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## dorkage (Jul 7, 2009)

Looks like it's going to be a nightmare putting the Immo2 ecu and cluster in the non CANbus 99.5 Golf. Not the end of the world if I have to split up the harnesses, but very annoying.


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## Demon Diesel (Aug 30, 2002)

dorkage said:


> Looks like it's going to be a nightmare putting the Immo2 ecu and cluster in the non CANbus 99.5 Golf. Not the end of the world if I have to split up the harnesses, but very annoying.


I can't see why it would be a problem especially if you are using the ECU and Cluster from the same car. 99.5 may be IMMO 1 and 2000 is likely IMMO 2. Once again easy way may just to turn off IMMO on the ECU. It will run without a cluster that way!

Also if you're doing a turbo upgrade... Get a better clutch than the G60/VR6 setup. It'a only good to about 225ft/lbs which is a mild tune on a TDI. You know how it goes. first you start with injectors... then the turbo and then next thing you know you are at 300ft/lbs and your "upgraded" clutch is a write-off!!!


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## dorkage (Jul 7, 2009)

Demon Diesel said:


> I can't see why it would be a problem especially if you are using the ECU and Cluster from the same car. 99.5 may be IMMO 1 and 2000 is likely IMMO 2. Once again easy way may just to turn off IMMO on the ECU. It will run without a cluster that way!


 No Immo in the 99.5. I found this spread sheet for running a 2000+ ECU in the 99.5, so just removing the immobilizer and wiring up a glow plug with my gas cluster might be my best bet. The 2000+ clusters have problems in the 99.5s because the Airbag and ABS use the CAN-Bus to talk to each other and the 99.5 doesn't have that. Is removing the Immobilizer as easy as removing the IC for it within the ECU? Or does the checksum of the ECU have to be changed?



> Also if you're doing a turbo upgrade... Get a better clutch than the G60/VR6 setup. It'a only good to about 225ft/lbs which is a mild tune on a TDI. You know how it goes. first you start with injectors... then the turbo and then next thing you know you are at 300ft/lbs and your "upgraded" clutch is a write-off!!!


The clutch is my old VR6 one, it has lots of life less. The "new" on in my VR6 is likely more worn than the old one. The plan right now is to get it working, run it and save some money on fuel. I'm going throw 10 litres every other day here and I'm not driving very far. Also, the Sachs VR6 clutch is good for 300ft/lbs


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