Meticulous prep work, 4.2 swap.

[Bdub2391]

I am picking up a 2002 AWN this weekend to swap into my 1998 a4 avant, 2.8. I have spent the last two or three days sorting through wiring diagrams and 4loops AWESOME charts, and have successfully managed to match 99% of the wires from the '98 body plugs to the corresponding wires on the '01 AWN harness. Apparently I got a little lazy with the labeling on two wires on the body plug side, so now I have to find them again in the diagrams and label them more clearly. I've been so focused on wiring diagrams and following bhusted and 4loops build threads to a T, the whole strictly using the 2001 ecu and the wiring for that, that I never stopped to think about the fact that they are using 2000 a6 engines.. a4v8swap on motorgeek clearly states that AWN from 2001 to 2004 can be used, with the ideal engine being ART from a 2000 due to no immobilizer. I simply strayed away from this build/diy because the wiring wasn't clear. That being said, I'm left with a few questions. The first being have I made this more difficult than it has to be, or am I on the right track? With my engine and harness not being changed from an older version to a newer ecu, would there even be the same ecu issues and wiring changes with this swap? Do I even actually need to use the '01 ecu instead of the '02 that came with the engine? My understanding of the reasoning for 01 ecu is its hybrid can-bus. If 02+ isn't hybrid does this make problematic changes to the engine harness? I can't find much on differences beyond "That's from a 2001 so it's a hybrid CAN-Bus ecu that can still accept non CAN signals as well. Do not get a 2002-up, as you'll have issues getting the ecu a VSS signal" - ddillenger. I have already ordered an '01 ecu and plan on cross checking the '02 harness pins with what I have sorted now, but even then.. Will a cluster change to a facelift model be required? I have found a few ecu pinouts, but none for the 2002 AWN, only wiring diagrams. I have slightly attempted to find a 2001 harness, as I already have wiring sorted for that , however I am unsure if a harness change is necessary.
Anything helps, thanks in advance.

[Bdub2391]

Thought I should mention that I am just now starting to read through tinytim's ENTIRE build thread to mine for clues, lol. Another thing I let slip my mind in the wiring conundrum.

[Bdub2391]

Thought I should mention that I am just now starting to read through tinytim's ENTIRE build thread to mine for clues, lol. Another thing I let slip my mind in the wiring conundrum.

Feeling stupid, as this would have taken a lot of work out of sorting the wiring. Oh well, I'm extra comfortable with the diagrams now...

[Bdub2391]

Feeling a lot less overwhelmed today. I was struggling to make sense of things based off of other build threads, diys, and tech articles so I broke down and bought a subscription for the a6 on alldata. I have officially completed pin outs of its ecu and body plugs. The differences weren't nearly what I had expected. I still need to organize the ecu pinouts as I just wrote down the pin number, wire colors, and where the wire went in the harness as I found them. As far as CAN-BUS goes, I'm pretty confident I don't have too much to worry about being as I purchased the '01 ecu. The '02 harness does have k line hook ups, so things are promising there. I feel like I have a good idea of the CAN wiring route in the engine bay, but I need to research the system itself a bit more to find out what might piss off the ecu or obd port if not connected. I'm hoping to isolate it to only necessities. Ecu arrives on Friday, and I pick up the engine, harness, and most of the other essentials on Saturday. I should be started on physical harness modifications by... Monday?

[Bdub2391]

Finally finished routing can bus and sorting through diagrams. Went to pick up the engine and other stuff yesterday in a pretty wicked snow storm. Unfortunately I haven't transferred the engine and parts from the back of my girlfriends avant to my garage. Once I do I will begin preparing the engine for its new home. There were a few bits taken off the engine that I wasn't expecting, but they have been provided so I'm not too worried. I do need a few other parts before I start the mechanical aspect of everything, but that gives me time to button up everything electrical. Excited to start the harness modifications as well as starting to remove things from the A4. I have decided that swapping in a facelift cluster is going to be worthwhile, so I will need to remove the gray 32 pin plug harness, wiper switch, and pedal harness from the parts car in my driveway. The cluster had already been removed, so a bit less work for me! All in all I am comfortable in saying I had myself far more flustered than necessary. Looking forward to moving forward, going to have a lazy rest of my Sunday.

[walky_talky20]

Nice work.

I'm sure the GF is loving the drippy V8 engine stuffed in the back of her Avant. lol. Post a pic. I want to see what that looks like in there.

[redline380]

What part of MN?

[thedanplasse]

I'm sure the GF is loving the drippy V8 engine stuffed in the back of her Avant. lol. Post a pic. I want to see what that looks like in there.

When I picked up my 1.8 long block I met the guy 2 hours away. He brought his truck, I brought my A3. He asked where my truck was, and I pointed at my a3, He laughed, we stuffed it in the back of the Audi, and off I went. Lol

[Nollywood]

Welcome aboard!

Personally, I would only perform this swap in a facelift car. Even last of the line B5 2.8 Quattro models are pretty inexpensive these days.

Please tell me your car is Quattro!

[Joe Jr.]

just a quick comment, you might want to check on your Garage description under your profile Avatar..Some weird graphics are going on here.