Shift scheduling, VCM scanner not showing 2nd gear?

[mikez71]

I've noticed a few instances in VCM scanner, it does not show me in 2nd gear, yet the graphs indicate I should be in second (rpms drop, speed still climbs)
Is this a tuning issue? Or do I have my VCM scanner settings incorrect?

Here is my tune.. 123TCCoff.2015.shift.noaddmod.inertia.tccslip.2018.TorqAdders.tqfactor.ttime-R3-maxprepress.hpt

Here is a log, at the 1:40 mark, I'm accelerating at 80% throttle, it shows 1st to 3rd, but the graph seems to indicate second was engaged...Log-0065-1GNSKBE0XCR266687.hpl

Also, just prior to that mark about 1:38 it finished a 3-1 downshift, by the time it finished shifting it was 28mph. I have the 2-1 downshift at 24mph (100% throttle)
Possible the 3-1 shift started at 24mph (1 second for shift time)

[TransGo Robert]

I've noticed a few instances in VCM scanner, it does not show me in 2nd gear, yet the graphs indicate I should be in second (rpms drop, speed still climbs)
Is this a tuning issue? Or do I have my VCM scanner settings incorrect?

Here is my tune.. 123TCCoff.2015.shift.noaddmod.inertia.tccslip.2018.TorqAdders.tqfactor.ttime-R3-maxprepress.hpt

Here is a log, at the 1:40 mark, I'm accelerating at 80% throttle, it shows 1st to 3rd, but the graph seems to indicate second was engaged...Log-0065-1GNSKBE0XCR266687.hpl

Also, just prior to that mark about 1:38 it finished a 3-1 downshift, by the time it finished shifting it was 28mph. I have the 2-1 downshift at 24mph (100% throttle)
Possible the 3-1 shift started at 24mph (1 second for shift time)

Your OSS is not reading, no idea why that is but it makes it harder to analyze your log. The problem looks as if your transmission is slipping badly in first and for quite a while after the 1-2 shift. That's all based on the VSS using your tune rear end ratio and tire sizes, but it would be much easier if we had the OSS reading like normal. Since the drop in input shaft RPM seems decent and crisp, my guess this is juts an issue where the computer is miss calculating the output shaft RPM for some reason.

[blindsquirrel]

Also would be much easier to make sense of if you made a log showing JUST starting from a dead stop, accelerating at constant throttle, and letting the trans shift. There's tons of distracting shit in the log I looked at - on/off throttle, normal cruise, goosing it, decel, etc. Just start the log in park, go to R, then N, then D, then half throttle and hold it until it's into 4th gear or so, then brake to a stop and stop the log.

[mikez71]

Wow! Thank you Transgo Rob and blindsquirrel!

I will check into my OSS signal and get a better log!

It doesn't always miss recording 2nd gear, and I don't -notice- slipping in first...
Could the OSS not be reading because I tried disabling the speed limiter? (changing general/source under the limiter tab from 'GMLAN' to 'calibration')

[TransGo Robert]

Wow! Thank you Transgo Rob and blindsquirrel!

I will check into my OSS signal and get a better log!

It doesn't always miss recording 2nd gear, and I don't -notice- slipping in first...
Could the OSS not be reading because I tried disabling the speed limiter? (changing general/source under the limiter tab from 'GMLAN' to 'calibration')

I have no idea if that will cause it or not, unfortunately the tuning side of things is not my strong suite.

[mikez71]

Hooked up a Tech2, got OSS signal! Looked normal, steady.
Reprogrammed ECM with limiter source to GMLAN, still no signal in VCM scanner!?

BTW I have 4WD so I guess the OSS sensor is on the transfer case....

Haven't been able to get a short log of it missing second, will try some more..

[TransGo Robert]

Hooked up a Tech2, got OSS signal! Looked normal, steady.
Reprogrammed ECM with limiter source to GMLAN, still no signal in VCM scanner!?

BTW I have 4WD so I guess the OSS sensor is on the transfer case....

Haven't been able to get a short log of it missing second, will try some more..

It must just be a VCM Scanner glitch then. The OSS is in the transmsision, you have to pull the pan to see it.

[hjtrbo]

The scanner is hit and miss with the oss. I had to put in a support ticket to get mine mapped.

[TransGo Robert]

The scanner is hit and miss with the oss. I had to put in a support ticket to get mine mapped.

Thanks

[mikez71]

Awesome, I did fill out a ticket and they have responded already! I need to send some files to them. Will update.