IAT is 39?

[eboggs_jkvl]

Ok, why is my scanning tool reading 39 degrees F when it is 83 F while I'm driving? Have I clicked the wrong PID or something? Having an IAT that low is probably great for not pulling timing but it's a lie and I'm sure the ECM knows that the IAT is at LEAST 83 because it is 83 here!


2007 E38 Corvette

[eboggs_jkvl]

I'm missing a post in here that suggested a broken wire.

When I have this tune in the car, my IAT is an average 166F I am still using the same wires, IAT sensor but now I read a correct temperature. I am using the same PIDs. I must conclude that there is something wrong with the first tune I attached.

Elmer

[joecar]

Elmer, I saw that your log file shows what appears to be a valid IAT so it can't be a broken wire (IIRC broken wire gives something like -39°F).

[eboggs_jkvl]

I only have 1 IAT PID to select? SAE.IAT

It reads perfectly on the 2nd tune in post #2 but goes to shit on the first tune post #1.

[eboggs_jkvl]

After further review, I see a 2nd IAT PID called IAT2. GM.IAT2

IS that what I really need? The IAT PID works just fine on the 2nd tune I attached.

[joecar]

Elmer, that is strange, I don't see how that could happen.

[eboggs_jkvl]

Elmer, that is strange, I don't see how that could happen.

Uh-oh. I think I'm in deep shit if you're stumped!

[joecar]

Can you make this happen simply by flashing in the file from post #1...?

[eboggs_jkvl]

Yep, absolutely every friggen time! That's what started this post! It's playing screw-screw with my mind!

[eboggs_jkvl]

The second tune is an E-Force tune from Edelbrock that is scaled down by 25% It throws off my DIC instant gas mileage reading by 25% and the "Remaining Miles" is a total joke. The first tune is by my local tuner that is NOT scaled and gives my DIC readings correctly. I would prefer to use the 1st tune but something is wrong in the tune.

Elmer

[eboggs_jkvl]

Here is my PID selection that I used for both scan files

[joecar]

Your E38 pid selection looks good to me.


Copy the tables/parameters from the first file to the second file:
- open the second tune as the current tune,
- open the first tune as the alternate tune,
- press the differences button (red left/right arrow), this brings up the Compare tab,
- do ctrl-A to select all differences,
- press the Update button (copies the tables that differ from alternate to current), wait for it to finish,
- press the Save As button and select a new filename.

Flash this in, check what IAT does, and report back.

[eboggs_jkvl]

If I pull that off without screwing it up or saying "oh shit" I should get a free Aussie Beer!

Ok, I'll give it a whirl and see what happens. :D


Elmer

[joecar]

I can send you a Fosters, but its brewed in the USA (under license). :)

[eboggs_jkvl]

Snort, I think I did it without messing up. It's almost 8PM here. I'll upload the resulting file on Wednesday and see what IATs I get. Thanks for helping the old folk! :D

Than



Elmer

[joecar]

No problem, do you still want the beer...?

[eboggs_jkvl]

No problem, do you still want the beer...?


Only if the "merge" doesn't make my ECM a paperweight.

I'll let you know what happens.


Elmer

[eboggs_jkvl]

Ok, we did the merge. I loaded it into the ECM and we have different data! My current temperature is 58 (early in the morning) and my IAT is -8 F. I will NEVER pull timing while driving at the North pole!

I will make another post with what I did next.

[eboggs_jkvl]

After the -8F I loaded this tune. I then ran a scan while I drove. Notice the sudden increase in IAT? There is something wrong with the EFI Alchemy (local tuner) tune that is blowing the IAT reading into never-never land.


Elmer

[joecar]

That makes no sense... in the log in post #19 IAT ranges from 75°F to 77°F.

Have you contacted Doc at EFI Alchemy...?

[joecar]

Elmer, so the one that produces correct IAT is the .tun file from post #2...?

[eboggs_jkvl]

That makes no sense... in the log in post #19 IAT ranges from 75°F to 77°F.

Have you contacted Doc at EFI Alchemy...?


I asked for his files during the dyno runs we made on Monday. I haven't received them yet. The IAT in post 19 seems reasonable and was going up as I drove. The entire scan was ~5 minutes and the full heat of the engine and the current temperature seemed like a valid reading. Yesterday it was around 80 outside and my IATs were much higher as the sunlight was direct and helping to warm things up in the engine bay. The car had been sitting in the garage after the test drive and the heat had built up. I averaged 166F for the short 1 minute recording. I simply was looking for the IAT change as the previous IAT was averaging 46F. I stopped, put in the e-force tune, immediately started the scan and the temp immediately was different on the IAT up to 166 AVG.

[eboggs_jkvl]

Elmer, so the one that produces correct IAT is the .tun file from post #2...?


As far as I can see, post #2 and post #19 produces a reasonable IAT reading. Both of these tunes are scaled E-Force tunes.

[joecar]

As a sanity check, while set the scantool logging, and wiggle the IAT connector and its wiring, see if the logged IAT is steady.

[eboggs_jkvl]

As a sanity check, while set the scantool logging, and wiggle the IAT connector and its wiring, see if the logged IAT is steady.



Well, I am driving the car over bumpy roads during the scan. IF there was a "wire or sensor condition" wouldn't my IAT be spiking high or low as I drive? The temp is rock steady. It's just stupid wrong for my ambient temp. The time I changed the tune yesterday, I was sitting still in the garage. The only wiggle to the engine would be the starter engagement.

[eboggs_jkvl]

If you really want me to wiggle the IAT I will but I can get the IAT to change at will with the tune change in the ECM.

[eboggs_jkvl]

I don't need no steeeenkin sanity check! I'm old! I have a good excuse already! :D

[joecar]

Lol, ok, I was eliminating any possible extraneous causes.

I pm'd Tech Support, if they see something they will let us know.

[eboggs_jkvl]

Sounds fine to me. When I noticed this, I was totally flummoxed. I didn't have any sane reason why it was doing this. Good luck. If you need more data, I'm available.

Right now, I running the E-Force tune and ignoring my DIC readings.

Later,

Elmer

[Tordne]

So just to confirm; you are seeing a difference between flashing two calibrations both with the same OS#?

[Blacky]

After further review, I see a 2nd IAT PID called IAT2. GM.IAT2

IS that what I really need? The IAT PID works just fine on the 2nd tune I attached.

Just a quick note on the differences between SAE.* PIDs and GM.* PIDs.
SAE.* PIDs must return the non-defaulted value of the PID from the sensor, whether the sensor has failed or not.
GM.* PIDs usually return a defaulted value if the sensor is broken. i.e. the GM PIDs are used to keep the engine running by not using failed sensor values. The GM.* PIDs are computed from other sensors or they use a default value if/when a sensor fails.
So for trouble shooting sensors, its best to use SAE.* PIDs as they will show the actual sensor value as seen by the PCM.

All that is assuming that the tune in the PCM is not faulty. A faulty/corrupt tune is possibly causing what you are seeing.

Regards
Paul

[eboggs_jkvl]

E-Force Scaled tune: OS 12614676 calibration 12597121 Appears to be giving correct IAT readings
EFI Alchemy Tune: OS 12614676 calibration 12597121 Gave a -8F reading this AM with ambient temp of 58. This was the merge result per a few posts back.

Is there another number you need confirmed? Both are the same OS.

Elmer

[eboggs_jkvl]

Can you tell if the tune is corrupted?

[Blacky]

I think the tune is screwed up. Take a look at the two images. You can clearly see where some tuning tool has "thought" the table was at a different address in the ECM's binary image. That large valley running through the middle is exactly what you would see if the tuning software has messed up the memory layout of the ECM.

Do you know what tuning software was used to create/edit the tune that is causing the IAT problems? If it was EFILive then we need to figure out what went wrong.

Regards
Paul

[eboggs_jkvl]

Well, shit. This may be the direct result of the hand held E-Force SCT tune tool. When my Supercharger was installed, the car would not run after the SCT tune was uploaded. A Rep from SCT went over to Doc's shop and used something (ask Doc) to revive the ECM as it had become a brick. They got it to run and then Doc immediately used EFILive to work up a tune to "step away" from the Edelbrock tune. We have been chasing a "dieseling" issue at shut down. I've had so many tunes from Edelbrock and Doc to try an solve that issue I'd hate guess how many I've loaded. I'm STILL dieseling at shut down. I do not know what base tune Doc used to create his work. It may have been a "historical" tune from a similar car that he adjusted for my car. It may have been a scratch tune from a base 2007 E38 2007 Corvette tune. I just don't know any more.

I fired this thread off to Doc and asked him to look in here and comment.

If Doc touched the car or me, we used EFILive.

Elmer

[eboggs_jkvl]

I think the tune is screwed up. Take a look at the two images. You can clearly see where some tuning tool has "thought" the table was at a different address in the ECM's binary image. That large valley running through the middle is exactly what you would see if the tuning software has messed up the memory layout of the ECM.

Do you know what tuning software was used to create/edit the tune that is causing the IAT problems? If it was EFILive then we need to figure out what went wrong.

Regards
Paul


That merge tune was where I "updated" from the non scaled tune into the scaled tune last night. (post #12) Could that have give a weird result?

[Blacky]

That merge tune was where I "updated" from the non scaled tune into the scaled tune last night. (post #12) Could that have give a weird result?

No, unless EFILive is causing the issue.

Regards
Paul

[Blacky]

Well, shit. This may be the direct result of the hand held E-Force SCT tune tool. When my Supercharger was installed, the car would not run after the SCT tune was uploaded. A Rep from SCT went over to Doc's shop and used something (ask Doc) to revive the ECM as it had become a brick. They got it to run and then Doc immediately used EFILive to work up a tune to "step away" from the Edelbrock tune. We have been chasing a "dieseling" issue at shut down. I've had so many tunes from Edelbrock and Doc to try an solve that issue I'd hate guess how many I've loaded. I'm STILL dieseling at shut down. I do not know what base tune Doc used to create his work. It may have been a "historical" tune from a similar car that he adjusted for my car. It may have been a scratch tune from a base 2007 E38 2007 Corvette tune. I just don't know any more.

I fired this thread off to Doc and asked him to look in here and comment.

If Doc touched the car or me, we used EFILive.

Elmer

If the tune was messed up (i.e. what is shown in the image) by another tuning package, then no amount of tuning/tweaking with EFILive (assuming EFILive is not causing the problem) would (or even could) resolve it.
EFILive can only change the data in the tables that you see, not in the surrounding areas before/after a table. That appears to be what has happened. The corrupt tune started modifying memory about 64 cells after the actual table started. That means it is probably modifying the controller's memory for 64 more cells after the table ends. Those 64 cells after the table ends would belong to a whole bunch of other calibrations that will be causing a multitude of unexpected behavior.

Regards
Paul

[eboggs_jkvl]

If the tune was messed up (i.e. what is shown in the image) by another tuning package, then no amount of tuning/tweaking with EFILive (assuming EFILive is not causing the problem) would (or even could) resolve it.
EFILive can only change the data in the tables that you see, not in the surrounding areas before/after a table. That appears to be what has happened. The corrupt tune started modifying memory about 64 cells after the actual table started. That means it is probably modifying the controller's memory for 64 more cells after the table ends. Those 64 cells after the table ends would belong to a whole bunch of other calibrations that will be causing a multitude of unexpected behavior.

Regards
Paul

Ok, with that in mind, what is the course of action to get everything back in sync? Full flash to stock by the dealer? New ECM?

Elmer

[Blacky]

Ok, with that in mind, what is the course of action to get everything back in sync? Full flash to stock by the dealer? New ECM?

Elmer

Cal-flash only is required. I checked the OS and it is ok.

When I said "EFILive cannot fix it" what I meant was EFILive cannot fix that *.tun file. If you cal-flash with a non-corrupt *.tun file then it will be as good as new, as you've demonstrated by flashing in a tune that allows the IAT to work properly.
The thing is how do you know what is corrupt and what is not corrupt. There is no easy way to tell. Who knows where a particular *.tun file came from and if it is really ok or not. To be 100% safe you should flash in a stock tune (or at aleast a known* good tune) and start from there.

* Known good tune = you or whoever supplies it to you knows where it came from and knows that it has not been corrupted by some other tuning program.

Regards
Paul

[eboggs_jkvl]

"I think the tune is screwed up" is very, VERY misleading and has caused me some heated discussion. The tune is corrupted and no amount of expertise can fix the tune as it exists. I don't know how the tune got corrupted but knowing that information will help in solving the issue. I'm going to see Doc tonight and he will be able to get my ECM back to square 1 with a cal flash. I have my stock tune from a few days after I brought the car home. I can only pray that my dieseling issue could also be a result of the ECM corruption. This should not be this hard. My tuner has done tuning on superchargers and turbos often and there have been no issues. Doc is an expert at this stuff and has given long hours with me trying to solve the issues.

This thread was a simple question on something that I couldn't logically explain. IN hind sight, it may have been better to ask Doc first and not post this up. I figured that I had bugged him enough and the problem was something that I was doing wrong. I want to make sure that there is NO insinuation that the tuner caused this issue. The tune was not "Screwed up". The file got corrupted somewhere along the way and has been a monster from that point on.

Elmer

[Blacky]

I want to make sure that there is NO insinuation that the tuner caused this issue. The tune was not "Screwed up". The file got corrupted somewhere along the way and has been a monster from that point on.
Elmer

I agree 100% that the person tuning the vehicle did not screw up.

Sometimes the word "tuner" is used mean the person doing the tune and sometimes it is used to mean the software/hardware package used to edit/flash the changes.
Sometimes the word "tune" is used to mean the actual changes made to the ECM and sometimes it can mean the tune file.

So you're right to make sure everyone reading this thread is aware of what we're actually saying...

Some software/hardware package* has caused the tune file to become corrupt. From that point on it was never going to work no matter who or what was making changes to the tune file.
The fact that the vehicle runs at all is (in my humble opinion) testament to: 1) The resilience of the ECM to continue operating even when its partially damaged and 2) skills of the tuner (i.e. person) who may have had to make a lot of other changes to a lot of other parameters just to counteract what the corruption was doing.

* I'd like to think it is not EFILive but I can't rule that out - yet. Although so far nothing indicates it was the EFILive software that messed up the file.

Please keep this thread updated with the result of using a stock file and tuning it again.

Regards
Paul

[Blacky]

This should not be this hard. My tuner has done tuning on superchargers and turbos often and there have been no issues. Doc is an expert at this stuff and has given long hours with me trying to solve the issues.
Elmer

One thing to note that a corrupted file like this is operating system dependent. So it may be that a tuner (i.e. person) could tune a hundred similar vehicles but never one with the exact same OS. In that case that one OS would be the only one that ended up being corrupted. In fact the corruption may have occurred while the ECM was being recovered in the first place.
This document explains some of the pitfalls of recovery.
http://download.efilive.com/Documentation/OS%20Compatibility%20Guide.pdf

Even GM's programming system will corrupt an ECM if the incorrect files are loaded into it. I believe EFILive is the only tuning package that will warn you prior to a full-flash if you attempt to program a non-compatible tune file into an ECM.

Regards
Paul

[yonson]

You are using the wrong IAT transfer function for the E-Force TMAP sensor, the correct transfer function is:

Resistance Temperature
563 150
715 140
918 130
1191 120
1564 110
2080 100
2804 90
3273 85
3837 80
4515 75
5337 70
6335 65
7556 60
9056 55
10908 50
13216 45
16092 40
19696 35
24239 30
30000 25
37352 20
46797 15
59016 10
74940 5
95851 0
123485 -5
160313 -10
209816 -15
276959 -20
368896 -25
496051 -30
673787 -35
925021 -40

[joecar]

yonson, welcome to the forum and thanks for your input. :cheers:

[joecar]

Well, shit. This may be the direct result of the hand held E-Force SCT tune tool. When my Supercharger was installed, the car would not run after the SCT tune was uploaded. A Rep from SCT went over to Doc's shop and used something (ask Doc) to revive the ECM as it had become a brick. They got it to run and then Doc immediately used EFILive to work up a tune to "step away" from the Edelbrock tune. We have been chasing a "dieseling" issue at shut down. I've had so many tunes from Edelbrock and Doc to try an solve that issue I'd hate guess how many I've loaded. I'm STILL dieseling at shut down. I do not know what base tune Doc used to create his work. It may have been a "historical" tune from a similar car that he adjusted for my car. It may have been a scratch tune from a base 2007 E38 2007 Corvette tune. I just don't know any more.

I fired this thread off to Doc and asked him to look in here and comment.

If Doc touched the car or me, we used EFILive.

ElmerElmer,

There's a few different things touching the flash there...

Yes, most definitely not the fault of the tuner (person), Doc would have no control over what you described, and no fault was ever implied; he would certainly be interested to see it tho.
you certainly ran into a good juicy interesting corruption of some sort :cheers:

It might be good to start from a known good tune, and copy tables to it one-at-time... keep us posted.