NefMoto

Had a friend ask me about coding the egt out today, I tell customers no normally, but he's an Audi tech so I was less apprehensive about it blowing up.

At first I codes out cdatr, cdats, and catr, and obviously it just fell on its face because I didn't realize I had to change the fueling now that it isn't hitting the threshold.

His sensors actually function fine the majority of the time, but I guess very intermittently, talking every couple weeks throw an implausible signal fault.
I ended up only changing cdatr and cdats to zero,
Which resulted in me being able to even unplug tje sensor without a fault, indicating it's ignoring the diagnosis of them, but as long as I leave them plugged in the car drives great.

Anybody ever use this as a work around for somebody whwre the egt seem to be properly functionING 99.9 percent of the time?

Like I said he's a master audi tech so he can monitor this from now on, on his own, and I'm awaiting feedback, but it might be good for people whose cars seem to exhibit it little or no symptoms of bad egt but for whatever reason are throwing a fault.

year make and model or the type of file your using?

I used an m box file

Have you tried this? per s4wiki:
You shouldn't have to touch these, but are included here for completeness:

CLAATR - Error class exhaust gas temperature regulation
CLAATR2 - Error class exhaust gas temperature regulation bank 2
CLAATS - Error class exhaust gas temperature sensor
CLAATS2 - Error class exhaust gas temperature sensor bank 2
Also check your other cdatr catr cdats hex location against the ones posted on s4 wiki. Ive had success using this process

I had no problem removing the sensors it's just then don't you have to modify the fueling? He wasn't having issues with the sensors functioning just an intermittent code. What I did seemed to fix the problem is what I'm saying

The ecu will now run off of calculated egts extrapolated from the o2 sensors. If you wanna mess around with the component protection fueling (bts) more read the stage 1 551m community thread. Youll need to adjust fbstabgm axis and tabgbts described in the LAMBTS category. If your giving the car a tune i would also change lamfa to cover fueling. That can be found in the community thread as well.

Bullshit.

OP:
CATR switches off actual enrichment, probably the most important one.
Also, you might want to adjust BTS so that it keeps EGT's in check.

Once again, I ONLY turned off the diagnostic portions. So I did NOT disable the CATR. At first I did, but that isn't what I intended. And yes it fell on its face and I realized I couldn't do that without messing with fueling.

So I ONLY turned off diagnostic. So sort of.like when you turn of cold light diagnosis of the tail lights to put on LED so that it doesn't check resistance. I didn't disable.the signal. I only told it ignore signal plausibility. And sensor resistance check.




Again, the car is NOT ignoring the EGT. In my opinion this is a much safer way to go about "disabling" the egt from people that are getting egt faults. Especially if the car is running fine as verified by a wide band or something.

And as far as the tuning faq. I actually own Kess v2 and ecm titanium. The real registered versions. So a lot of the things are defined in their drivers. And actually they'll make any drivers for me I want.

So to reiterate again, if you disable CDATR and CDATS, and leave CATR alone, the vehicle will no longer throw any egt faults for the signal being implausible, nor for the sensor resistance being faulty,  and the ecm will still use the EGT for fueling calculations.I have the innovate motorsport wide band, and I also have a thermocouple with a testing meter so I can verify fueking and egt independently.

You need to learn to differentiate between when the egt model is used, and when the egt sensors are used. Your statement was incorrect.

You're wrong. Not surprising if you use ecm titanium lol.

Here is how it actually works:
1. EGT sensors are used only in the ATR module, which is a closed loop controller. The target is a fixed "never exceed" value. The feedback comes from the EGT sensors. The control parameter is lambda. The more EGT, the lower the lambda is driven, to control the EGT. BTS runs off of simulated EGT's that has no connection to EGT sensors whatsoever.
2. When you disable diagnosis, what happens is, when the EGT sensor errors out, the value momentarily jumps to maximum 1000+C and ATR will fully enrich down to the flammability limit. It will not recognize it as a fault condition and just drive lambda into the ground.

Thus the car will intermittently puff black smoke at totally random times and bog due to the super rich lamdba.

Does the ecu use any feedback from the 02 sensors to arrive at the calculated value?

No.

I think that misnomer started from tabgm being referred to as "temp at O2 sensor", then it gets regurgitated as "O2 sensor temp". Now it seems people think the O2 sensor is reporting temps.

It's mostly load, rpm, and airflow, then corrected by target lambda, ignition angle efficiency, etc

Edit: assuming you're referring to ATM, prj's text you quoted was ATR specific

I didnt mean the o2 would be measuring the temp but that the ecu would be calculating a theoretical temp in there based on ATM. I didnt describe it in the best way, I understand. I figured the o2s and a few other inputs were what was used to come up with the exhaust temp model. I see that its more iat, load and rpm based. Thanks for correcting me.

Ignition angle.

I blame the wiki: it says something about removing the O2 requires fixes to the "EGT model" which is a misnomer. It should be the "O2 sensor temp model".

I'll fix it time permitting... or maybe dd will beat me too it :)

Thanks for the explanations, fellas.

That's even worse.

Whoever came up with that? Documentation clearly says it is temp at cat.

Are you volunteering to help correct the wiki? TIA.

APR has it labeled as "EGTbank1OXS"  in ECU Explorer and MarkP titled the graph "EGT at Primary O2" in his commonly used excel template.

I use Titanium because I bought it as a package with Kess V2. I don't only or always use it, and I'd love to buy winols.

This I did in hex.

But since I don't know how to find maps and make def files yet, its nice to be able to shoot an email off to italy and have a definition by 1 AM. I have lot to learn still. I don';t have nearly as many issues as a lot of people on here claim to have, mot sure if its because people are using the pirated version or what.

That being said, I did exactly what I've described, my friend is an Audi Master Tech, it's not doing anything you're saying. Fuel trims are fine, AFR is fine, no black smoke, zero faults.

I understand how the EGT work for the most part, and yes what Ive done it will make it wrong wrong if they wig out while driving, but these aren't doing that.


So yes, I understand that the vehicle runs off the lambda and EGT and then when the narrowband EGT exceeds the EGT limit then it richens the fuel map to get the EGT down. So I fully understand what I did, which is, I told the car I don't care what you think abouyt the sensors, and their resistance or their value its outputting just take it at face value.


I realize that Titanium has its share of bad reviews and isn't as advanced, but I've had no problems tuning a lot of cars with it. I certainly have FAR fewer problems than I ever had tuning with any of the companies I used to pay 400+ dollars to for their over conservative tunes. I really don't know why titanium gets the rap it gets from people. I use a combination of things, and Id love OLS, but I really like not having to do any checksum calculations, and I like their customer service, they handle the more technical things I don't understand and leave me with the maps to mess around with while I learn the more advanced stuff you guys can do with ols. For now, this makes does what I need it to, and anything else I use tunerpro or a hex editor.

Yeah, I don't do EGT deletes, I would like to learn about it to know, but with my customers I tell them I won't do it.

This was a one time shot in the dark favor to a friend.

Where can I find more information on it so I can figure it out better? I was just basically going off what the wiki was saying, and I guess there's something about it described incorrectly?

I'll search again butr is there a good thread describing the EGT stuff, my understanding was these narrowband sensors just read a small range and triggered something with the lambda enrichment based on the EGT...When I disabled the last bit it fgell on its face when I'd get in it, then enabling that bit again allowed the car to run great, logged real time lambda, timing, boost, and saw zero issues, car has now been driving since the day I made this post with no faults anymore and they would come back same day before.

So, people on here are saying it shouldn't have worked but it seems to be working fine. And because people said that stuff I contacted my buddy and had him check everything out again with VCDS an the factory tool as well and no issues at all.

http://nefariousmotorsports.com/forum/index.php?topic=199.0
http://nefariousmotorsports.com/forum/index.php?topic=9161.0

Thank you sir for helping without the elitist bullshit some other people spew up on here. I understand how the EGT and Lambda stuff works I just don't know what to change to completely eliminate the EGT sensors if I wanted to. And I could tell as soon as I told it to ignore that the car was really unhappy when it reached the EGT threshold and that made it start to pull timing and boost because the AFR was off.

I'll have to sit down and read through this. I still plan to stick with my policy of not tuning them out I just don't trust my customers to not blow their engine up if something goes wrong I don't want to delete something like this and rely on the customer to not just throttle down if something goes wacky with the fuel pump or something and it starts running slow.

It will do it every single time that the EGT sensor shorts and shows 1000+ C EGT.
There is no diagnosis so the PID controller just goes nuts and enriches to the flammability limit.

As the intermittent contact/PCB goes worse and worse you will start noticing this while driving. It is possible now it only does on cold start which is not noticeable.

This is fact, it is not up for debate. Read the FR and stop writing walls of useless text.

You only think it's good because you don't understand why it's bad (yet).

"doveryai no proveryai"

The issue here is that you're modifying these tables with the assumption that the person that defined them is correct. It's a dangerous assumption to make.

Also, prj is likely correct re: the failing egt. It just sounds like yours is sporadic enough to not meet the diagnosis criteria.

It does meet the diagnosis criteria. What this man has done is disable diagnosis and keep control enabled, knowing that the sensors are going bad.
Already that is a pretty big fail. What makes it more epic is still recommending this fail approach after being called on it...

I skimmed. I didn't catch that, and agree.

Can you confirm what CATR is set to?

http://s4wiki.com/wiki/Tuning#EGT

Lol....once upon a time,  cars didn't monitor their sensors and tail light bulbs and shit for the tiniest little blip and throw the car into limp mode.

And whatever the ecm is seeing, is some tiny minute issue that's not effecting it at all.

Would I do this to a random customer car? Nope, but my buddy is an Audi tech and he knows what it's supposed to feel like when it's running right. It's been 6 months now, and it doesn't pull timing, detonate, run lean, or anything.

I mean,  I've seen temp sensors that do weird things like, read in their linear manner as designed, then when it goes from say 80 degrees Celsius, to 81, it jumps to 87, and then back down to 83...whatever is going on with his egt is something similar, for all I knowant the signal problem is at a temp below the enrichment threshold.

Honestly,  I'd much much rather do what I did, that straight out tune for an egt delete, yet people do thst all the time.

Its no different to me than owning a pre obd car, believe it or not people used to have to pay attention to how their car ran to figure out if a sensor was failing.

This won't work on every egt sensor, and there are some people who shouldn't be trusted with it,
But here's the deal he didn't even have me modify the requesting load, ignition timing or anything.

And also why are we pretending like there's no i knock control? This is a non issue.

You're mostly right about that, if we're talking about possible issues with EGT sensors and ECU's reaction to it. Apart from that accented part.
It does "something". It does enrich badly when your EGT shorts out. You keep insisting that you did stuff right when clearly that is not the case.


I can only quote prj here for great justice.

Look. prj's position is pretty clear; you disabled diag, but not EGT enrichment.

If what you said is true, and you don't need diag to tell you the EGT (or anything else) is going bad because you're leet, then you don't need our advice (or anyone else's advice) or any ECU diag. You're omniscient. Go ahead and disable all the diag in the ECU and stop posting questions :P

The car will sporadically enrich because the EGT sensor is going bad, and you'll know it is because... your EGT sensor is going bad.

The solution being

1) disable egt enrichment (you never said what CATR is set to)
or
2) fix your egt sensors

Enable/disabling diag has nothing to do with the fix; it is just preventing the ECU from telling you your EGTs are going bad.

Honestly I'm not claiming to be omniscient or know everything I'm nowhere near the best tuner in here, a but I am good at diagnosis, and I am a dealer trained VW and Audi master technician as well. I merely wanted to share something I found out that may work for some people, and despite the fact that I've seen the car and logged it, there's people telling me what I'm saying is impossible and its not. The questions I post are about ecm tuning which I still have a ton to learn about. Telling me that because I know about ecm disgnosis, I shouldn't need to ask about tuning, isn't really true. One of my main sourcs of income is answering questions for people about diagnosis on websites online. Doesn't mean i know how to tune a car.

People are making the assumption that whatever is going on with the signal that is causing the fault is either not the ECM to enrich at the correct time, telling the ECM to enrich when it shouldn't, or that it definitely will do so at some poiny. Without seeing what it's actually doing, which I have, that's not really necessarily true.

The only thing that I'm claiming, is that the ECM pays attention to the EGT signals all the time, and therefor it's possible for the ECM to throw a fault for the EGT signal being out of whack even if the problem with the signal is that it's reading funny down at lower voltages well below the enrichment threshold.

It is definitely possible for a sensor to read incorrectly at one part of its range and not others. As I stated I've seen coolant temp sensors that will start out at 44 degrees and read fine until it hits say 72 degrees then drop off to -40 degrees and then start reading Fine Again all the way to full operating temp, I've even seen them do that on the instrument panel side but not the ECM reading side. I seen fan switches that will turn the fans on at 25 degrees celcilus, then the engine gets a little warmer they shut back off and then they get back on again at the proper time. I'm not surmising that it's possible. I've seen it 100 times in the course of working at the dealer and in my own shop over the past decade. Ive had customers decline the repair because they don't have the cash and seen the car for years after that still functioning the same way. Should it be replaced because it's malfunctioning? Probably, but is a fan switch that turns them on from 30 to 35 Celsius. Then shuts them off and operates properly
from 85 to 110 Celsius going to cause an issue with over or undercooling? No.

The assumption that the problem with the EGT signal is incorrect in the operating range that deals with enrichment fueling is incorrect. The assumption that it's necessarily going to degrade further and begin to malfunction in that range down the line is incorrect. And that has nothing to do with tuning at all. That is vehicle diagnosis related.

So, I'm not saying I'm even good at tuning at all, but I do know how sensors function, what the ECM is looking at, and what can cause a fault.

The only claim I'm making in this thread is the following.

The ECM looks at the signal and resistance of the EGT sensors at all times. It only actually does anything in response to that signal is if the sensor voltages crosses the threshold for enrichment per the setting in the ECM. If the EGT sensor does not read in the correct manner or the resistance of the sensor changes, then the ECM throws a fault. The ECM throws the fault regardless of whether or not the malfunction occurs at a temperature range that the exhaust is at idle, or if it's at a temperature range consistent with moderate throttle freeway cruising, or full throttle running lean as hell with a bad fuel pump. So if the signal malfunction is happening at a very low temperature where the ECM only pays attention to the signal for the purpose of signal diagnosis, but functions properly in the temperature range that deals with enrichment fueling, it will not cause any issues with fueling.

Will it get worse some day and start to malfunction in a range of temperature that could cause misfueling? Sure, but will it DEFINITELY? No. Will all EGT sensors fail in this manner? No. And will an EGT sensor that's malfunctioning below the temperature range used for enrichment fueling cause a fault, but not effect the entirichment strategy if you disable the signal diagnosis. Yes.

Again. You absolutely shouldn't do this to a customer car, but if it's your own personal car, and you can log the air fuel ratio or you have an air fuel gauge with a wideband installed, and can verify the Afr is correct, then fuck spending 600 dollars on EGT sensors.

A simple glance at the FR will tell you you are wrong about CATR. Please don't present things you are assuming to be true as fact when there is actual documentation FROM BOSCH that says otherwise.

Ok I'll check it out. I gotta see if he'll let me borrow it to weld in a bung. I know how to admit if and when I'm wrong and do my due diligence.

Haven't we found a few cases where the documentation was actually wrong? I'm not talking in this particular case.

I can tell you with almost 100% certainty that if diagnosis is masked and CATR is enabled, if the EGT sensor reads enough to activate enrich, you will see enrichment on ME7

I could be wrong, of course.

I don't disagree. Saying to always trust the documentation was where my point was.

You're not wrong obviously.  We ALL know this to be a FACT from much testing logging and experience that what PRJ and the FR says is true and the OP is wrong.

What the OP did and his assumptions because he has an "audi tech" that knows how a car is supposed to "feel" is laughable at best.

3 pages of nonsense for a basic part of the ECU's functions being debated is crazy.  Alone the fact that he hasn't taken any logs to see this for himself is enough to end this thread, never mind having it bumped after months.