2015 Silverado throttle closing during run

[KLUG'S SS]

Well as the thread title says I've got a customers 2015 Silverado with just a tune of course, K&N intake and exhaust work done and can't seem to get the damn thing to keep the throttle 100% open throughout a run. Whether it's just 0-60 or up to a 100 or whatever. Here's the kicker though only seem to be having the issue in just 4wd at the moment, 2wd the throttle stays at 100% the whole time. Now the reason I'd like to have the throttle stay open 100% in 4wd is because can't launch the truck in 2wd without blowing the tires off.

Anybody run into this issue yet? I've done plenty of reading up on this newer operating system and playing around with the tune and I am well aware of the driver demand tables, torque management etc.... Now I've got the driver demand tables raised up about 20% in the "100" row and up shift torque management completely disabled because I noticed after a shift the throttle not wanting to come back to 100%. Like I said though mainly in 4wd. What am I missing here on this thing? Posting this from my phone til I can get to my laptop later so I don't have any logs or tune files obviously at the moment. Just curious if anybody has seen this behavior on a 14-15 truck yet?

It seems it's not just at certain rpms and whatnot it just closes the throttle randomly all over the place by sometimes 20-40%!

[ElecTech]

You need to log ETC Source to find out what is commanding the throttle shut.

[KLUG'S SS]

Right, exactly! I was looking for that in the PID list for the main table and did not see it. I need to look again I guess. I am in need of some glasses pretty bad. lol

[Higgs Boson]

post your tune

[KLUG'S SS]

Yes sir was going to post the tune file as soon as I got to my laptop a little bit later. Just on my phone right now.

[KLUG'S SS]

Looking back over some logs I guess this turd is closing the throttle at times in 2wd as well, just not as severe. Tune file attached now. Obviously I understand not the correct way to approach it but in this tune file I just went ahead and increased the bottom two rows of the driver demand tables by 20% and raised the peak torque table overall by 20%. Just made the two significant changes as a test basically to see if I could get the damned throttle to stay open throughout a run.



Erick 2015 Silverado tuned.hpt

[ElecTech]

Right, exactly! I was looking for that in the PID list for the main table and did not see it. I need to look again I guess. I am in need of some glasses pretty bad. lol

The ETC Source and other "Source" PIDs are usually in the "General" section of the Scanner PID list.

[KLUG'S SS]

Yea I know and I found it, just looked right past it like an idiot. Like I said I do need glasses pretty bad! Lol. Went and finally took my eye exam three weeks ago now but just been so darn busy haven't gone and actually ordered the glasses themselves yet.


Thanks though ElecTech.

[Joshtuning]

Sounds more like a traction control issue throttle body shouldn't be closing even with stock driver deman tables

[Howes]

i'll bet it's seeing wss differences and dialing u back. these things are such over engineered pieces of shit!

[KLUG'S SS]

Anybody else have any suggestions? Truck is still cutting throttle back and is driving me nuts trying to get it resolved! Lol.


I've tuned MANY gen 3 and gen 4 trucks over the past almost decade now and have never had an issue like this but I do know these new trucks are a different beast.

[Higgs Boson]

zero out Accel Thresh table in Fuel Cutoff

this one blows my mind: all your engine torque management tables are stock. you need to max out (96,674) the axle torque values, brake torque limit, etc. of course you are being limited. that is 101!

[KLUG'S SS]

Well sir been down that road already as well as in at one point with this truck, I did have all of the axle torque values etc.... completely maxed out and it did not help my throttle limiting issue at all. I just went back to stock with all of those tables again because I have made so many different changes at different times trying to solve this issue I am just trying to keep a sanity check. If that makes sense.....

[Higgs Boson]

better to rule them out if you are chasing an issue.

max them out and keep logging pedal vs throttle and your tqmgt pids, etc.

[KLUG'S SS]

Right!

[KLUG'S SS]

I am going to post up a few screen shots and or log files for this beast today.

[Sneakyws6]

My 2014 Sierra with the 6.2 does the same thing. Hammer it with the TC off in a speed that I know it should hit the high end of 1st or 2nd and once it drops into the gear and plants you it abruptly closes the throttle and then feathers the power back in.

Very irritating for sure.

[KLUG'S SS]

My 2014 Sierra with the 6.2 does the same thing. Hammer it with the TC off in a speed that I know it should hit the high end of 1st or 2nd and once it drops into the gear and plants you it abruptly closes the throttle and then feathers the power back in.

Very irritating for sure.

Yes it is! Well I'm glad to see someone else has this going on. Well I mean I'm not because it's sucks. Lol. But I have been tearing my hair out trying to fix this and have still come up empty.

[KLUG'S SS]

Frustrating as hell for sure. I am far from a "noobie" tuner and I have never come across an issue like this that I could not resolve! The problem definitely does not lie within the driver demand tables or the peak torque table which in more heavily modded trucks those tables can have an impact. But on this truck with nothing more than an intake, exhaust and a tune of course the truck isn't surpassing the stock numbers in like the driver demand tables.

[KLUG'S SS]

I just tuned a 2014 with the 6.2 last weekend and that particular truck had 100% throttle the entire time going wide open throttle, doing several pulls up to 90+ the throttle never deviated from the 100% commanded pedal.