LS1 PCM COS3 Not Reading Boost After Software Upgrade. Anyone else?

[finishline]

Thanks for taking a look guys. I've got a 2003 vette running COS3 with a 2 bar map sensor properly scaled. This exact tune was reading boost before I upgraded to a newer version of software. Granted it was a few months ago that the car was tuned but now for no reason I can't read boost. File attached if you need to see it.

I've resorted to throwing various other tunes into spare ecms I have and powering them up in my personal vehicle. They are all doing the same thing. I've also changed out the MAP Sensor for another 2 bar and I get the same results. I changed the scaling on the map sensor ( C6301 ) back to a 1 bar scaler number and I can watch the car with Key On Engine Off read around 48 and as I increase boost toward 15 lbs I can see it go up towards 90. That tells me there is nothing wrong with the sensor or wiring. To me that only leaves the software.

I'm desperate for any and all suggestions.

Thanks for your time.

Randy

20529

[joecar]

Randy, post your log files.

Which kPa pids are you logging...?

[finishline]

SAE Like the COS Upgrade says. But I did try everything that was related to MAP and still nothing.

I've done a lot of these Joe. First time I've ever seen this.

[joecar]

Try doing a full flash of your current tune file.

[finishline]

I've done that a dozen times and I get the same result.

[joecar]

Try logging these pids, let see what the PCM is doing:
- SAE.MAP
- GM.MAP
- GM.MAP2
- GM.MAP3
- GM.MAP4
- GM.MANVAC
- GM.MAPBOOST_DMA
- GM.MAPU
- GM.MAPV
- SAE.BARO
- GM.BARO
- GM.BOOST
- GM.BOOST_DMA
( some of those have units "Volts" )

[GMPX]

Randy, I don't remember on the LS1 PCM but is there another PID related to MAP? Something like GM.MAP and not an SAE PID? (Edit, Joe just posted some MAP alternative PID's to try)
We did have to make some changes to the SAE.MAP PID recently as the set up of that PID was changed by GM. It shouldn't have affected anything but there might be something funny going on.

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I just finished loading a laptop that has never had efi live on it before. V7.5.7 ( Build 309) I'm going to do a full flash of that vette file I did over a year ago. I'll pull it off my tuning laptop without opening it and copy to the new laptop and then do a full flash and see what happens.

I'll also log all the pid Joe suggested even though I have tried a few of them already. I want to be very thouough so we don't miss anything. I've been beating my head against the wall for 2 full days before I asked for help.

Thank you. Give me 20 minutes.

[finishline]

Guys,

Same results. I'm totally lost. The new computer had nothing on it like cax files or anything.

I was only able to log the additional pid baro. All the others were grayed out.

Baro was showing 99 at Key On Engine Off.

[finishline]

Randy, I don't remember on the LS1 PCM but is there another PID related to MAP? Something like GM.MAP and not an SAE PID? (Edit, Joe just posted some MAP alternative PID's to try)
We did have to make some changes to the SAE.MAP PID recently as the set up of that PID was changed by GM. It shouldn't have affected anything but there might be something funny going on.

I'm going to delete the EFI Live from the new computer. What Version of the software should I download to get in before you made the change to the SAE.MAP Pid? If it works with the older version then we will have our answer.

[GMPX]

July 2016 should be fine.
http://www.efilive.com/latest/software-release-july-2016/

There should be more than just the SAE.MAP PID on the LS1 PCM for monitoring MAP.

[finishline]

Downloading and rebuilding again. I'll double check again with the new file.

Here is the tune and the log file. The car is not running, key is on and I have a regulated air supply going to the map sensor to simulate boost.

I logged everything that was not grayed out and was related to Manifold Pressure.

At frame 176 I started adding pressure.



20531
20530

[finishline]

Forgot to mention we also logged GM.Map Voltage
which shows the scanner seeing the voltage continue
to rise but the MAP is Pegged at 105.

[finishline]

I can't think of anything else to try. It's got to be a software issue.
What else can I provide to get this moving forward and a bit closer to finding an answer?

[GMPX]

Is it doing the same thing with the older software release?

[finishline]

Yes, it's doing it with the older release as well.

I should probably add that I was only reading the original tune that was already installed into the ECM with the newer software. I guess it could be something written into the tune?

[GMPX]

Randy it is getting hard to follow the processes here.

You said this
This exact tune was reading boost before I upgraded to a newer version of software.

Now you've gone back to the older software and there is no change, you still can't log boost.

How many tune changes have happened since it worked? Can you put in the ECM an older file?
Do you know what software version you had before updating to go back to that?
There has been no changes to the LS1 files since the July release you just downloaded so it shouldn't be an issue with something accidentally getting changed in the tune.

[finishline]

Randy it is getting hard to follow the processes here.

You said this
This exact tune was reading boost before I upgraded to a newer version of software.

Now you've gone back to the older software and there is no change, you still can't log boost.

How many tune changes have happened since it worked? Can you put in the ECM an older file?
Do you know what software version you had before updating to go back to that?
There has been no changes to the LS1 files since the July release you just downloaded so it shouldn't be an issue with something accidentally getting changed in the tune.

Sorry for all the confusion. I'll try to clear things up. I installed a cos3 into a boosted 2004 truck. It wouldn't read boost above 105 KPA. So I gave up and came home. At home I had a spare 04 ecm so I blew that same tune into that ecm and hooked it up to my personal truck to power it up (Key On Engine Off). I also hooked up a radiator pressure tester to the 2 bar map sensor to simulate boost. With this setup I still couldn't read past 105 kpa with 10 lbs of boost. I conducted numerous tests and always came up with the same result.

I then decided to blow a tune from a boosted vette I tuned a year ago into that same ecm. Testing came up with the same results. No readings above 105 kpa. ((That's the tune file where I stated it had previously read boost with that tune back when it was in that customers car a year ago.)) I provided a copy of the boosted vette tune file and a small data log when it was hooked up to my truck for testing.

I pulled the 04 computer out of my truck and programmed my personal (03 Tahoe) ecm with a cos3 and ended up with the same results again.

So, at this point I've tried new tunes and tunes I've done a year ago and all had the same result.

Now, I get a spare laptop that has never had EFI Live on it and I program it with the latest software. No CAX file or anything. Just the basic program as you would download it off the site. I go through all the above steps again with the same result.

So, I delete everything from the new laptop and load the July release. Go through all the above steps again. Same results.

I've been working on this for over 3 days now and I've done so much testing it makes my head spin. I think I may have gone back to one more older release as well and done all the testing again with the same results.

I provided a tune file and short data log for you guys when I was testing with the vette tune. It's posted previously in this thread. It shows the Kpa reading with key on engine off of around 99Kpa. I then added boost pressure with the radiator pressure tester of around 10 psi. You can see where the pressure goes from 99 to 105 and gets stuck at 105 but you will note the voltage continues to climb to 4 plus volts.

It's like the software doesn't want to go over 105. I've read where someone said that will happen if your running a stock tune because the VE Table stops at 105. Makes sense to me. But I'm running a cos3 that goes way above that and I should be reading boost.

I'm heading up the road 60 miles to another guy that has EFI Live that I tuned 4 months ago. We are going to use his laptop and software to read his car and see if it reads boost using the radiator pressure tester method. If it does then we are going to try to use my equipment. I hope that gives us some answers. Is it possible something in my V2 is corrupted?

I'll post up the results as soon as we finish testing.

I'm sorry for the confusion. I was constantly running tests between my post but was trying to keep you guys up to speed on what I was testing and the results. Trying to keep things short and not be long winded left a lot out. I hope things are more clear now. If not ask away.

Thanks again for everyone's time and attention. As always, I'll post back with my answers.

Randy

[finishline]

PROBLEM SOLVED!!!

Thanks for everyone's time and helpful suggestions!

Here is what we found out. I don't proclaim to understand the internal workings of the ecm but testing proves this out. During the following testing we used 2 different versions of the software, 2 different V2 boxes and 2 different laptops. The V2 boxes were one old Black one ( Mine ) and one newer Blue one ( Customers ) if that makes any difference.

We tested a 64 Vette running a Maggie SC as I had previously tested. KEY ON ENGINE OFF= Both V2's would read atmosphere pressure. Apply 10 LBS of Boost and both V2's would stop at 105 KPA and not register boost. We went for a test drive and both boxes would register and data log boost. No problems!

I believe what is happening is as long as the engine is NOT RUNNING eg: KEY ON ENGINE OFF--- The ecm is stuck in Baro Pressure Measurement Mode and there is probably a hard limit in the tune of 105. As soon as the ecm registers crank rotation it will now start measuring boost. We also found out with a stock operating system you can not register boost over 105 even with a 2 bar map sensor properly scaled. I believe it is due to the 105 limit in the stock VE Table.

Long story short: I caused myself a lot of lost time because I didn't realize the ecm was in Baro Measurement Mode. I had always read in service manuals it was a momentary sampling right at startup with key on. I didn't realize it continued that way until the motor started. It was just a coincidence this happened after a software upgrade.

[joecar]

...
I believe what is happening is as long as the engine is NOT RUNNING eg: KEY ON ENGINE OFF--- The ecm is stuck in Baro Pressure Measurement Mode and there is probably a hard limit in the tune of 105. As soon as the ecm registers crank rotation it will now start measuring boost. We also found out with a stock operating system you can not register boost over 105 even with a 2 bar map sensor properly scaled. I believe it is due to the 105 limit in the stock VE Table.
...
Thanks for posting this, this is something to keep in mind (SAE.MAP pid will not read above 105 kPa while engine is not running).

[GMPX]

Thanks for posting this, this is something to keep in mind (SAE.MAP pid will not read above 105 kPa while engine is not running).

Thanks for reporting back Randy, and what you've said there Joe makes perfect sense when you think about it.