absolute throttle vs commanded throttle

Gmc-dude · January 8, 2015

When I am driving I have noticed that my commanded throttle says 100% but the absolute throttle is 83-84 ish and never 100%, anyone else ever noticed this or does anyone know why it does this??

8.1HD/ALLISON · January 8, 2015

Gms nanny programming to keep people from tearing up stuff. Get a custom tune and you can open it up.

TJay74 · January 8, 2015

it is not that simple on the new direct injection programming. From what I was reading on HP Tuners website the tables are all tied in with the actual torque output now. Some of the guys tried to just max the table out in hopes of getting the throttle response and it didn't work like that on this generation. That was about as far as I read into at the time

8.1HD/ALLISON · January 9, 2015

Oh gotcha, didn't see year/make.

WendysOrBust · January 9, 2015

it is not that simple on the new direct injection programming. From what I was reading on HP Tuners website the tables are all tied in with the actual torque output now. Some of the guys tried to just max the table out in hopes of getting the throttle response and it didn't work like that on this generation. That was about as far as I read into at the time

Do you have a link? Interested to see how the newer direct injection engines are programmed.

nuclearxp · January 9, 2015

You can start here: Parameters - GM.

I could probably answer some basic questions if you want.

The section you're looking for would probably be "gm > engine >torque management > general".

redwngr · January 10, 2015

Very interesting, but seems to reference older engines rather than the direct injection ones.

Verifies the use of different programming (including different stoichiometric ratio) when ethanol is run, for those engines with a fuel composition sensor.

TJay74 · January 10, 2015

I was just browsing around the GM tuning sections setup for the DI engines and got into some of the threads. Everyone was trying to older generation tricks of maxing tables out only to find out that throttle response was even worse. Then they said it is based off of the commanded torque values and that some effort had to be put into those tables as they didn't work like the prior generation did.

That was as far as I got into it as it was past my knowledge level with HPT. I have it and use it on the transmission side, but I mainly leave the engine side alone.

Higgs Boson · January 22, 2015

The real answer is whatever you are using to log Actual Throttle is using an old PID. It reads the voltage as 84 or whatever % but it is 100. The tuning systems/companies still have this legacy measurement from older PCMs but also have new ones that read correctly for the E92/E78 as well. Update your equipment.

Gmc-dude · January 23, 2015

The real answer is whatever you are using to log Actual Throttle is using an old PID. It reads the voltage as 84 or whatever % but it is 100. The tuning systems/companies still have this legacy measurement from older PCMs but also have new ones that read correctly for the E92/E78 as well. Update your equipment.

ok thanks