NefMoto

Could a 1.8 ecu be used to get wideband tuning capabilities for an s4 tune?
Does the 1.8 ecu see a larger voltage range for the o2 inputs?
I will look for pinout diagrams to compare.... just a thought after a long midnight shift at work.

Would be simpler to use a BEL 03+ 2.7T ECU that has built in wideband control.

i think the bel would work... just gotta defeat the immo?

I think the cost would be cheaper for two bank monitoring with better logging options... i could be off base but that was my thought. 

So is the 03+ 2.7T ECU ME7.5 then?

Maybe we should all switch... ;)

From a posting on either Wayot or Quattroworld, I remember Mihnea from MRC Tuning stating that he was able to integrate wideband sensors to be utilized with the the B5 RS4 ECUs.  While he did not mention his process, I always wonder how he had accomplished to integrate that feature.

I believe the advantages of integrating wideband sensors would be having more accurate data for the ECU to process and not having to purchase or rely on third party hardware and software.

It would be a very cool thing if someone was able to figure this out.

If we could compare a 2002 and 2003 2.7T ECU hardware, we could determine if they are any different. If the differences are only in software then it shouldn't be that hard to add support.

I am very intrigued as well.

Comparing the 2 ECUs sounds like great idea!

By the way, I just joined today, and I find this website heavenly!

I will buy an 03 2.7 ecu off eBay once my car is back on the road.  I will need help determining if the hardware is compatible though. If it is then I just need 2 o2 sensors and to copy the o2 voltage map into my tune, or would it be more prudent to tune the file from the new ecu?

This would be truly awesome

I assume you would need to ensure the ECU connector is compatible, then disable the immobilizer, and get the oxygen sensors the ECU is expecting. I would go from the stock tune in the 03 ECU and work from there.

ecu #s
4Z7907551R-  2003 ecu a6 2.7
4Z7907551S - 2004 ecu a6 2.7
4Z7907551AA- 2004 ecu a6 2.7

o2 part #- W0133-1793935 which is about $120 x 2

you can pick up an ecu on ebay for about $180-$250, then sell your ecu for the same amount or more if it has a tune on it.

$240 for dual bank wideband monitoring with ecux and vag-com logging...the kicker is that you probably need to replace your o2's anyway.

Closed loop control far from lambda==1! :)

I'm also into this but still a bit unsure if the 03+ BEL ECUs are really wideband. It was stated on Audizine by a member of EPL in the Tial605 result thread, but if you look into the 4Z7907551R Winols file there is GGLSV and LR indstead of GGLSU and LRS which is the normal chase for linear lambda sensors.

The Hardware of the ECU is different for sure as its ME7.1.1. Even the chasing is different.
I have ordered a 4Z7907551AA ECU and I will find out  ;)

Would be pretty easy to verify by looking at the schematics... I'll try to do so later today... If it has 5-wire O2 sensors, then it is.

I have tried to figure it out with ETKA but wasn't very successful. For the 03+ ARE and BES engines it seems that it has narrow band.
If you have the wiring diagramms it would be nice if you can look it up.

I asked the c5 a6 and allroad guys on audizine which ecus had wideband... no answer yet. Not even a snide comment, which you would expect.

yea 5 wire will give it away, and the ECU hardware WILL be different as the wideband control circuit is built into the hardware of the ECU, its not in the sensor itself.

Honestly i would just get a Innovate LC1 and hook that up and use the 0-5v and feed your rear 02's(assuming you deleted them) and theres your "wideband" signal.  you wont get a lambda reading, but voltage is fine and can be converted in excel easily.

I thought most adc's/dac's will support up to 5v but i would double check with that before doing that :)

It's not about getting a wideband signal to the ecu, it's about closed looped fueling on the whole operating range.

Yea thats tough, closest thing i can think of is the b6 3.0 ecu, i believe those are wideband.

Did we ever confirm if the 03+ 2.7T ECUs have wide band control?

Going off of part numbers for the O2's, No they do not, just the 3.0's had the wideband sensors.  This is per Bosch's website.

I looked up o2 sensors for the b6's and they were all 4 wire.
What was the latest Audi model to carry the 2.7?
 I'm thinking the allroad... I will look into it.

i looked and 2005 appears to be the last year the 2.7 was used,  all the o2 sensors i found were 4 wire... another rainbow with no gold at the end.

Yes, i replaced myself front O2 sensors on few 2003-2004 allroads 2.7, and all of them have 4 wire narrow sensors.

Has anyone checked out this site?

http://www.boschautoparts.com/VehiclePartFinder/Pages/VehiclePartFinderResults.aspx?MAKE=AUDI&MODEL=S4&YEAR=2001&CAT=OxygenSensors

I looked briefly and couldn't find anything but I wasn't very sure what year/model I should be looking at.

I looked around some more on there and have to agree.  No direct swap.

Got the part #? Ill check in the morning if it will help.

I just checked now (forgot about this thread lol).

Elsaweb diagrams show 4 wire O2 sensors for an 04 BEL Allroad.

No wideband here guys, sorry.

Schematics are attached if anyone wants them...

No point posting on audizine about anything beyond backlight audi rings or some crap like that.

Time and time over again my technical questions go totally unanswered there and once I went after few people who have build threads over there, 90% of them just pay some shop to do the build and then brag all over audizine about their dyno runs.

For technical questions quattroworld.com is the place, there are quite few people who know their stuff in B5 s4 section.

LOL!

Ain't that the truth... the community for this car really went to shit when every 16 year old with a hard on could afford to buy one.  Most of those posers would be appalled at how ratty my car is.

bring back this topic because some of you are searching for a 2,7t ecu with wideband,
for example the 2003 a6 2,7T do have wide band: 4Z7907551N.
its a me7.1.1.
i have such ecu at home and can try in my rs4 or s4 if it starts or not (with immo off)

i think we need an additional 12V at pin 21 in older 2,7T for this ecu.

i let you know..

Looks like the cars with that ECU fitted use narrow band sensors.

I have a 2005 allroad C5 with a BEL 2.7.
It is a 4Z7907551T, my spare eBay ecu is a 4Z7907551S, they appear identical inside and out.
Do I just check the wire harness on the front O2 sensor(s) for 5 wires?

yes, and also you can check block 31 with vcds/vagcom.
if you have lambda values there (at idle 1.00), you have wide band, if volts are there, not..

Checked, it is volts.

Has been there any progress in this direction? Is there an easy way to convert 2.7T to Wideband? Considering this as a perspective platform for tuning after playing with 1.8T. The only one thing stops me - there is no known complete solution for Wideband.

Possible ways I see:
1) port Wideband handling from ME7.5 into ME7.1 via asm code injection, use second Lambda as an input for voltage, then translate that voltage into Lambda value and patch those places when ECU goes to open loop, instead use closed loop & input from second lambda.
 
2) Convert ME7.5 from 1.8 T, lot more changes will be required because of different engine volume, different count of cylinders, different hardware (modification of SY_ constants, lot more patches in asm code & wiring)

Answered here: http://nefariousmotorsports.com/forum/index.php?topic=14138.msg114849#msg114849
Your first proposed option is viable to some extent, but that's still too much work with questionable benefits.