: Spoke to Jesse today about tunes/new mods

06-19-09, 09:45 PM
Jesse was gracious enough to spend a good 20-25 minutes on the phone with me today to discuss my concerns regarding various issues including issues with upgraded tunes-
1- The inability to recieve e-mail updates on our handhelds for example a 160 tstat is another HARDWARE, not software problem. Jesse is waiting for SCT to come up with a firmwear solution otherwise some handhelds could be disabled trying to upload at this time.
2- On similar note those, like me, that have been pulling fuses to upload tunes will have to continue to do so again until SCT comes up with a solution.
3- If you already have his "base" tunes and a CAI/modified airbox and are adding the 4-inch intake/MAF you do not need a tune upgrade but it would help to dyno the car and make sure the MAF does not need adjustment
due to improper air/fuel ratio's(the tuner could manipulate the MAF)
4-Jesse feels the additional engine coolant reservior he is offering will drastically reduce heat soak especially at sustained higher speeds- I will let you guys know as it goes in on Tues.
5-I was very concerned about the need for an updated tune- Jesse assured me that with my #3 max perf/pulley tune I should be fine for my upgraded exhaust(AR Headers plus corsa), 4-inch intake/MAF, 5% crank pulley- A/F ratio may need some slight adjustment while dyno testing post install

Hope this provides a useful update.....

06-20-09, 01:40 AM
Well, i'm dead in the water as far as Jesse's tune is concerned.
After my tranny swap, GM has updated my ECU/TCU and the handheld now reports "Unsupported ECU".

I contacted Rudy at SCT for a new firmware update.
I updated the FW to ( was ). That didn't help.

SCT thinks it might be that GM changed part numbers and don't match Jesse's tune anymore.

If anybody with a working handheld can see of the GM part numbers where changed. These are my new part numbers:

OS Part number: 12632176
Transmission: 24249179

SW partnumbers:

You go into vehicle info -> vehicle info and it will show the part numbers.

The only other problem it might be is that the new TCU hasn't had a change to attach(?) to the ECU. I t takes a number of key turns (starts) before this happens.

I don't understand what the trouble with emailing tunes is.
I was able to talk to the handheld using the X3LWUpdater 2.2.11 from the SCT website. With it you can download new tunes into the handheld (*.CEF or *.LL3 files).


06-20-09, 03:00 AM

What i've noticed in the stock ECU / TCU update:

ECU: does not run as rich anymore. My tailpipes stay remarkably clean now.
TCU: When manually downshifting during a stop, the car does not "lurch" forward.
But: both ecu and tcu are still very sluggish compared to w4m tune! I endup driving in manual mode 95% of the time.


06-20-09, 06:37 AM
Hmmmm. I wonder whether this means a software upgrade from GM is forthcoming for the rest of us? Or has the tranny hardware changed?

06-20-09, 08:08 AM
It would be helpful if Jesse could chime in here especially in light of Hans situation- as AF pointed out this could eventually affect all of us.

Hans did they inform you of this update before they did it?

06-20-09, 09:38 AM
It is just a mismatch on the serial numbers. Call Jessie again, he can shed some light on this but I have run into this issue on other cars.

06-20-09, 01:42 PM
I hear from Rudy, my original transmission partno was 24249178. now its 24249179

06-20-09, 02:21 PM
Hans I am sure Jesse could fix this assuming the SCT guys get this firmwear problem resolved.

06-21-09, 11:26 AM
Jwa999, I dont have access to anything other than my tuning files with the sct stuff. I cant do anything with the stock reads. Everything has to be sent to sct for them to convert back to something i can even mess with.

As for the part numbers. I dont believe that is valid, as the only part number software wise is the 2429179 that you have in your transmission at this time. It matches what you already have.

However. If you are using a new transmission, It has a new computer in it so i am thinking that it is just still unlocked and is not requesting a seed key pair, so therefore it is already unlocked and the sct programmer is trying to send a key to the tranmission when it is not asking for it, so it is just waiting blindly for the key to be sent when it aint going to happen.. The period of this behavior can actually be monitored with a DMA pid request sent to the ecm, on a new ecm or car, there is a timer that drops on successful ignition cycles and it usually starts with a value of $FF. Well 8 bit with a 1 scaler which means a english value of 255. So the ecm has to be started/driven/shut off that many times or less before it will "Lock". Durring this time also, other things happen in the tune ive noticed, Like different calls to different tables that arent usually used after it is locked.. So it is just breaking still, and you should just wait and then after 500 or so miles, then put the tune back in. That way you can see if there are any issues with the new trans.. You probably just had a dud transmission component.. 5th gear lost is really odd...

06-21-09, 12:47 PM
Rudy read the old stock files and told me the transmission part number was changed.
I have 400 miles on the new transmission. I'm still trying to be gentle with it. Yesterday i had a very slow shift after it had been sitting for about 15 minutes. Almost thought, lord, not again. This will be my last GM Automatic transmission car for sure.
So i will try the hand held again in 100 miles.

Questions about the hand held:
1) I updated the Firmware to ( was ) from rudy@SCT. Is that a proper FW for the CTS-V?
2) What is the problem with emailing tunes? I'm able to talk to the hand held with one of my XP PCs.
One some PCs, the driver doesn't seem to work very well or doesn't get installed. Then the hand held powers up but immediately shuts down again.