Will an ECU from a 2000 B5 S4 work for a 2000 C5 A6? Both are 2.7T 6spd. part numbers inside
Thread Starter
AudiWorld Member
Joined: Oct 2005
Posts: 481
Likes: 1
Will an ECU from a 2000 B5 S4 work for a 2000 C5 A6? Both are 2.7T 6spd. part numbers inside
This is the S4 ecu:
Audi S4 NA MY2000 2.7T 8D0907551A S0003
And this is what the A6 needs
Audi A6 NA MY2000 2.7T 6-spd 4B0907551K
Are these compatible?
Thanks!
Audi S4 NA MY2000 2.7T 8D0907551A S0003
And this is what the A6 needs
Audi A6 NA MY2000 2.7T 6-spd 4B0907551K
Are these compatible?
Thanks!
AudiWorld Super User
Joined: Nov 2004
Posts: 4,212
Likes: 1
It definitely works to a degree
We put the ECU from a 2000 A6 2.7T 6MT into a 2000 S4 for diagnostics and the car started up fine.
So, the question of whether it will work could use more specificity. It will work at a basic level, for sure.
However, if you want to actually use the ECU, you might have some problems. For instance, if the car is equipped with ESP, you might get fault codes for no communication with ABS sensor, or something like that, but likely wouldn't throw CEL.
Trying to cross BEL engine-based ECU's (like a 551R) with an AEB engine based ECU is a bit different, but 2000 to 2000, there's at the very least a basic level of compatibility.
So, the question of whether it will work could use more specificity. It will work at a basic level, for sure.
However, if you want to actually use the ECU, you might have some problems. For instance, if the car is equipped with ESP, you might get fault codes for no communication with ABS sensor, or something like that, but likely wouldn't throw CEL.
Trying to cross BEL engine-based ECU's (like a 551R) with an AEB engine based ECU is a bit different, but 2000 to 2000, there's at the very least a basic level of compatibility.
Guest
Joined: Jul 2003
Posts: 9,715
Likes: 1
Yes - depending on year. I looked at circuit dia's for S4 and A6 and found only
The Brake Boost control to be missing from the S4.
I don't know if Key security was present in 2000 A6 but if it was you'd lose that also.
I don't know if Key security was present in 2000 A6 but if it was you'd lose that also.
Thread Starter
AudiWorld Member
Joined: Oct 2005
Posts: 481
Likes: 1
Thanks to all! i ended up using lemmiwinks to retard timing 3 degrees and won't need a stock ecu...
i wanted to buy the s4 ecu to use as a stock ecu for long trips.
Now, since ignition timing was causing the engine to be more audible i tried retarding it. And it did the job.
The car is so much smoother now and without boost the engine is soooo quiet. I'm just wondering how much power loss is there by retarding the ignition 3 degrees. Mileage does not seem to be worse... too early to tell though.
thanks to all for all the help!
Now, since ignition timing was causing the engine to be more audible i tried retarding it. And it did the job.
The car is so much smoother now and without boost the engine is soooo quiet. I'm just wondering how much power loss is there by retarding the ignition 3 degrees. Mileage does not seem to be worse... too early to tell though.
thanks to all for all the help!
Trending Topics
Former Vendor
Joined: Aug 2007
Posts: 162
Likes: 0
I'm not sure what you're trying to accomplish...
If you retard timing, the engine will produce less power with the same amount of fuel.
3 degrees will honestly not make a difference, especially when you're talking seat-of-the-pants.
If you're going for fuel mileage, realize that aftermarket ECU programming still retains factory closed-loop operation under cruise. So on the highway, it's trying to maintain stoich just as the factory ECU does. Your mileage will actually increase under cruise with aftermarket programming, as the motor usually runs more ignition timing.
3 degrees will honestly not make a difference, especially when you're talking seat-of-the-pants.
If you're going for fuel mileage, realize that aftermarket ECU programming still retains factory closed-loop operation under cruise. So on the highway, it's trying to maintain stoich just as the factory ECU does. Your mileage will actually increase under cruise with aftermarket programming, as the motor usually runs more ignition timing.
AudiWorld Stories
Bringing Audi to Life for Audi Fans
10 Strangest Audi Designs That Actually Made Production
Joe Kucinski
2027 Audi Q7 and SQ7: Audi Upgraded EVERYTHING!
Michael S. Palmer
Audi Unveils Absurdly Cool New Supercar: 10 Things You Need to Know!
Verdad Gallardo
The Highs & Lows of Every Audi C-Class Generation
Joe Kucinski
Top 10 Most Expensive Audis Ever Sold on Bring-A-Trailer
Brett Foote
10 Audi Features & Options We Miss the Most!
Joe Kucinski
Audi Recreates Crazy-Looking Speed Record Breaker From 1935
Verdad Gallardo
Coachbuilder Recreates the 1995 Audi TTS Concept
Verdad Gallardo
Every Audi V10 Car Ranked!
Joe Kucinski
AudiWorld Super User
Joined: Dec 2003
Posts: 7,152
Likes: 0
Maybe he is trying to get away with lower octane fuel for long trips?
But anyway, your info will prove very useful to me I also have an A box I want to use in place of a K box.
If you recode the box, is it a complete and prefect replacement?
Actually, my A box has an APR chip on it. I was going to write APR's K firmware to it and recode the box. I fugured then it would definitely be a perfect replacement for the K box. Just not sure if I even need to do this.
Stephen
If you recode the box, is it a complete and prefect replacement?
Actually, my A box has an APR chip on it. I was going to write APR's K firmware to it and recode the box. I fugured then it would definitely be a perfect replacement for the K box. Just not sure if I even need to do this.
Stephen
Thread
Thread Starter
Forum
Replies
Last Post
A-Sixer2K
A6 / S6 (C5 Platform) Discussion
9
Jan 15, 2007 07:34 PM
Ben the Ben
S4 / RS4 (B5 Platform) Discussion
4
Aug 8, 2006 11:17 AM
2000 S4 chipped ecu into a 2000 A6 2.7T, has anyone tried this yet? considering they have the same e
Chipped2.7Tip
S4 / RS4 (B5 Platform) Discussion
5
Dec 22, 2005 09:57 PM
2000 S4 chipped ecu into a 2000 A6 2.7T, has anyone tried this yet? considering they have the same e
Chipped2.7Tip
A6 / S6 (C5 Platform) Discussion
4
Dec 22, 2005 05:49 PM
