NefMoto

I cant seem to get Oxygen Sensor (readiness) to pass on ME7.1.1. I followed all the instructions on the S4 Wiki about how to disable Rear 02 and Delete them and over time i've gotten "very" close. The last piece is getting CDLASH to pass i believe. Since the Sensors are not physically plugged in the CDLASH piece covers the "Slow Response" CEL's, But on B6S4 this routine seems to block overall oxygen sensor readiness from completing. So i cant just turn it off or it never passes. ive tried configuring the car to think it has 2 sensors and it still is trying to pass the rear 02's. ESKONF is setup for no rear 02 as well. It never throws a code.... but the failed oxygen sensors test drives me nuts.

Gremlin provided a great document on what needs to happen to pass and i believe im stuck on one piece now. In the Test it has to go above voltage X and below Voltage Y. My initial thought was to make sure that both of those values would match up with 0V since thats what it sees all the time...

Question is, Am i on the right track or am i going to have to physically DB 00 out the routines that ask for this task to be completed... Guidance on where to go next would be helpful so i can finish this up before i need an inspection sticker. I literally have 1-2 hours of free time a day with a 1 & 5 Year old... or else i would be a much bigger nerd. Thanks in advance.

Sounds like a reasonable start to me

no luck. and it seems my Rear 02's have to start the process, or at least initialize the process of either Voltage / Resistance, or a combination of both before the tests will complete and start the fronts.

IF someone can point me in the right direction it would be helpful

Any chance you can just hook up a rear o2 and hang it somewhere safe?

Fall back would be to just weld in a bung and have a rear O2 actually in the stream, then you just need to avoid an efficiency code

I have the rom setup to do that, one B6 has them ziptied to the top of the transmission, mine has no cats and its fine. I really wanted to be complete about removing them all the way. I guess i should give up at some point... but ive invested a lot of hours that would be wasted i feel.

I hear you, its a huge pain.

Maybe this will help, maybe not, not sure how many differences are between 7.1 and 7.9.10, but I went through a month ordeal to sort this out on my ECU. The goal was the same - code out rear lambda to use the bung for external wide band and maintain readiness tests passed.

I switched off the following:

CDHSH
CDHSHE
CDLASH
CDLSH
CWDKAT
CWKONLS
CWLSH

On your ECU some of these might be hidden behind some other things, like ESKONF words. But that did not help, I was still getting a DTC and readiness was no go. At this point I started looking into the code. The first thing was that the diagnosis procedure for CDLASH had a bug (yes, really, I saw it factory fixed on another SW version) which despite CDLASH turned off was not setting internal status flags to all OK (wrong code jump), so I fixed that with a tiny code patch. IIRC this sorted out the readiness problem, but no DTC, so I also switched off the DTC through clearing CLAHSHE. I looked around the code and it is still beyond me why the code is reported with all these flags turned off and I have to also turn off the class byte. Probably a similar bug to the one above, but once I got it working I moved to other things. I am also not 100% sure that all of these have to be changed, but again, it works, so does front lambda, so I don't bother no more.

Tried all this Current solution i have in testing on my car is

CLRSHK - 5
CLRSHKEB - 0
CLRSKA - 0
ESKONF correct
CDHSH - 0
CDHSHE  - 0
CDKAT - 0
CDLASH - 0
CDLSH - 0
CDLSHV - 0
Cwkonabg - 4
cwkonls - 17
CWLSHA - 0
CWDHLSH - 0

If someone can tell me what im missing. that would be great.

 

Have you tried also with CLAHSHE and CLAHSHE2?

Thanks for the update! I did not turn those off because i never get to the point where i have a Fault. It just never finishes running the Oxygen Sensor Checks.

Hold on, it just occurred to me, what do you mean by "never"? For me it took some driving and several warm up cycles to clear out... And it gets reset to the initial state on each flash (OBD one at least).

I could drive this S4 around for a year and Oxygen sensors never passes or fails... So technically it works as is... because i can have one system fail... but i want to know what system is holding up the process.

Going to post a thread showing you how to do this with an 8 byte patch

Already got it working. Thanks though. I had help but the command jumped over a couple of pieces to allow the whole routine to finish.