what radio connections are required for engine run?

[tallon]

I eliminated all radio connections from my harness but am aware that you need to use a security code when the battery is removed. Is this possible without radio or with minimal connections and what connections are required? Maybe something can be removed from the ecu?
The engine is going in a custom chassis build so I took all unneeded circuits out of the harness. I heard of K-line but don't know exactly what it is. I kept the IC with immo fully intact in the harness.

2000 4.2 Audi A8 Quattro 40v AKB

[27litres]

AFAIK the radio security coding is purely for the radio itself.
The radio does send information to the dash for radio station and Nav info (where fitted), but I doubt that will affect it from running at all.

[tallon]

Ah ok seems silly that I asked now. I thought the security code would have been tied in with the immo and everything, it seems like the norm for everything in the car to be connected in some way. thanks

[27litres]

I thought the security code would have been tied in with the immo and everything, it seems like the norm for everything in the car to be connected in some way. thanks
The immo itself is housed in the dash module (instrument cluster) and uses a coil around the ignition barrel to energise the key transponder which sends a radio signal to the module. To get into that module you need a PIN with VCDS.

With what you're doing, I think you'd be better off with some sort of immo-defeat.
I believe this can be handled at the ECU, but you need to talk to someone who knows the software and ECU's.
Theres a really good B5 4.2 conversion (http://www.audizine.com/forum/showthread.php/554401-4-2L-V8-Swapped-B5-A4) thread going at the moment (click on the link), and forum member ddillenger really seems to know his stuff.
They'll probably tell you to get rid of the A8 ECU and swap in an A6 one...

[tallon]

You think the 40 valve would be any different?

Also I do have a 3.7L A8 ecu since I am using a 5hp19 auto trans like the 3.7 used and I thought maybe that would work and I think there was no immo but not sure. But whether it'll be the same for the 40v is still a question