2018 Yukon 5.3 6spd update

[staytuned]

Earlier post was new 2018 yukon with rough idle that comes and goes, poor accelerator response and surging as it runs up to about 45mph, converter hunting or coming on and off.

Fixed idle by raising it to 675 in neutral/park and in gear. Wife loves it, also helps with backing up as before it wouldn't move when releasing brake.

Added up to 22% to the driver torque demand to improve throttle response. Also turned off converter through 4th. TCC only in 5 and 6. This fixed surging and struggling in lower speeds/gears.

Lowered the TCC slip desired and raised the ramp rate and pressure (didn't change but 6 actual psi on scanner) Tried 0 slip rate and more aggressive ramp numbers but it was not happy and kept jumping in and out. Slightest movement of throttle makes TCC release and re-apply. Would like to figure this part out but it feels real good.

Shortened shift times by 10% and turned up shift pressures a bit along with slight inertia table increase. I did this as I also increased the minimum spark tables to 8 degrees. This made the upshifts feel awesome and better through the gears but kickdown from 6-4 or 5-3 or 4-2 were way too harsh. So maybe the removal of torque management would be better.

Also removed V4.

The wife now loves her new car. We have been to the dealer 3 or 4 times with concerns and even drove another with some of same issues except the rough idle problem. They started a case but I said EFF it and new nothing would get done. I've tuned more than a few things, mainly diesels and TCM's but we wern't looking for more power, just some drive-ability.

Here is my map, If anybody has any Ideas to add I'm open. Would like to tune the VVT so it is used more for performance than EGR, Ideas all ways appreciated.20018YukonTerrisTune5.hpt

[5FDP]

Removing TM isn't really what I would suggest.

I'd lessen the shift pressure at above 300ft lbs for those full throttle shifts, you're a decent bit higher than stock and further than I would have gone.

I can get most of the shifting stuff done with minimal shift pressure changes and mostly with shift time, on-coming pressure presets and a slight reduction in the shift torque factor.

Haven't had a problem with harsh downshifts or more harsh than they were stock. Altering the DD tables could maybe play a roll in the downshifts.

Power enrichment stuff could be played with if you wanted too, they are overly rich from the factory and a little bit lazy.

Haven't touched the VVT yet on my truck but my previous truck I start retarding the cam in all 3 tables (low/med/high) a lot sooner. These trucks they don't even have anything in the low/med and only in the high. (excluding the egr effect).

[staytuned]

Removing TM isn't really what I would suggest.

I'd lessen the shift pressure at above 300ft lbs for those full throttle shifts, you're a decent bit higher than stock and further than I would have gone.

I can get most of the shifting stuff done with minimal shift pressure changes and mostly with shift time, on-coming pressure presets and a slight reduction in the shift torque factor.

Haven't had a problem with harsh downshifts or more harsh than they were stock. Altering the DD tables could maybe play a roll in the downshifts.

Power enrichment stuff could be played with if you wanted too, they are overly rich from the factory and a little bit lazy.

Haven't touched the VVT yet on my truck but my previous truck I start retarding the cam in all 3 tables (low/med/high) a lot sooner. These trucks they don't even have anything in the low/med and only in the high. (excluding the egr effect).

Thanks for the input. The harsh downshifts went away when I put the minimum timing tables back to stock. I had set both minimum tables to 8 degrees entire map. It up shifted good but that made forced downshifts bang. So maybe the reduction in shift torque would help keep it from pulling timing on the shift ?
Thanks

[5FDP]

I've set the minimum spark to -5 to 0 degrees without issue. Never done positive timing because I still wanted it to pull timing but not -20 to -30 degrees.

[Higgs Boson]

min timing table is the minimum final result, rather than amount of timing pulled out.....

8 degrees of spark lead isn't going to create a harsh shift but in combination with some of those other changes it might.

I would put your DD table back to stock and pursue other means, if you edit your DD in a vacuum (without redoing/considering many other parts of the torque model) then you are going to get a lot more intervention from the system, getting demands for more power but expecting to be producing less at the same time and trying to accommodate both.

[DHC]

It sounds like you are getting the wifes rig worked out, good for you.

I played with the DD tables too much and like Higgs said, there are too many factors interacting with the DD tables. I found that the DD tables would introduce weird shift behaviors, weird torque management events, KR, just weird stuff, as the spread from cell to cell got bigger. Makes sense, with little pedal input the demand may increase too much from cell to cell. It caused me all kinds of headaches for a while. I have since spent more time decreasing the "spread" and making sure the transition zones are smooth and gradual all the while maintaining WOT when pedal is 100%.

[staytuned]

It sounds like you are getting the wifes rig worked out, good for you.

I played with the DD tables too much and like Higgs said, there are too many factors interacting with the DD tables. I found that the DD tables would introduce weird shift behaviors, weird torque management events, KR, just weird stuff, as the spread from cell to cell got bigger. Makes sense, with little pedal input the demand may increase too much from cell to cell. It caused me all kinds of headaches for a while. I have since spent more time decreasing the "spread" and making sure the transition zones are smooth and gradual all the while maintaining WOT when pedal is 100%.

She now loves the way it drives. She was ready to trade it in and we didn't even have 1500 miles on it yet. The map I posted above makes it drive like it should have from the factory. She can actually back it up without everyone making fun of her at the shop now. LOL
I did smooth the starting and ending transitions in the DD table but did crank it up about 25% at the 20% pedal position range, and didn't touch any negative numbers. I feel like now I can start figuring out how to tune it for a bit more power for when I drive it. Wanting to work with the vvt and timing next and trans torque limiting.

[DHC]

That's awesome. Glad its working out for you.