4L80E Line Pressure

Hello All!
I am still a bit of a Noob when it comes to the programming aspect of performance, so I totally need some help from someone with more knowledge. I am posting this in the transmission and forced induction section for two different issues.

To start, this is a turbo (S366) third gen 5.3 with a GT2-3 cam and 2000 LS1B w/ COS 5. Its in a heavy 4x4 with a fresh SRTA 4L80E 2K stall and 3.73's

The question I have in this thread, is do I have the line pressure correct for my application? The trans builder said to have all the line pressure in by 25% throttle or so. I'm sure there are a number of things wrong with this tune, including the shift points, but I am doing it one at a tome right now. Could someone please tell me if I'm going to burn up this trans? Especially when I begin to tow. (4-5K lbs)

THANK YOU!!

The shift base pressure tables (D0701,2,3) are used during shifts...

PCM calculates the base running (non-shift) pressure based on calculated engine torque is calculated from VE/MAF... so if you got VE and MAF correct (not under-reporting) then base running pressure will be good.

I generally do this:
- set D0701,2,3 to start sloping up from (0,0) and to reach 96 psi by 354-399 ftlb.
- set D1108,9,10 to 0.20-0.25s.
- set D0801,2,3 to control shift feel (I aim for a nice firm shift upto 33% throttle, and for solid wheel chirp above 50% throttle).

I also do this:
- set D0960,1,2 to zero everywhere (let the VSS upshift/downshift tables control shifting).
- set D2904 to 99-100%.
- set D2903 to 90-95% (you may want to adjust this down if it's too jerky).

Some people also do this (I don't always get changes with this):
- set D2901 to some higher value.

Also log GM.TFMPRS and GM.TCCMODE.

I see a delay of 1 second from PE enable to PE actually kicking in...

you need to set B3609 to zero.

You should use more fuel when PE kicks in, set B3618 to 1.25 EQR throughout, to be safe.

You should start ramping up B3647 earlier, from say MAP 80-85 kPa (which is quite a significant load).

Also take care of this:

make each WOT downshift MPH below their corresponding WOT upshift MPH...

for example: each of D0925, D0930, D0935 mph should be below its corresponding/respective D0910, D0915, D0920 mph

( and same for all the other corresponding WOT shift pairs )

Quote:

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Originally Posted by joecar

Also log GM.TFMPRS and GM.TCCMODE.

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Log GM.TFMPRS...

and also connect a 300 psi pressure gauge to the line tap on the side of the trans case, and do a few test drives while observing the gauge, this will tell you if line pressure is good (line pressure should go up easily with throttle, at WOT you want to see something like 200-230 psi)... your trans builder should have told you to do this.

Joe! Thank you very much! I am making changes tonight and will try them tomorrow.