4L60 to 4L80 (dumb) question...

[swizcore]

This is a 5.3 from an '01 Silverado which originally had a 4l60 but during my swap I moved to a 4l80e from a vehicle I drove a handful of times and the trans functioned perfectly.

Since getting this build on the road for shakedown, one of the first things I noticed is how quickly it will up shift through the gears.

My first thought is the tune. If all I did in the trans-tune was change trans type from 4l60 to 4l80 (without changing any of the other settings) would this be the obvious result?

Should I start simply by segment swapping a stock 4l80 into my tune to overwrite those 4l60 settings?

(As I type this, I realize how dumb of an inquiry this sounds to be but I'd rather not assume.)

Thanks for any help.

[5FDP]

You must do the segment swap if you are running the 4L80e now.

[Alvin]

yes must do a segment swap still.

[swizcore]

Went for a drive tonight after doing the segment swap and verifying the reared ratio was correct but it's still doing the same thing.

As soon as I take off at gradual throttle, it instantly shifts into second and then third.

Here is my tune, perhaps I'm missing something obvious.

Swizcore_Base_210420.hpt

[dhoagland]

Do you have any logs?

[swizcore]

I went out to record a log but it started snowing so I'll try to get one tomorrow.

[5FDP]

Are other parts of that tune correct too?

You say the engine is from a 2001 truck but the computer still has all 1999 data in there. So if you are running the 2001+ fuel system you'll need to update that too because the injectors aren't the same.

[swizcore]

Are other parts of that tune correct too?

You say the engine is from a 2001 truck but the computer still has all 1999 data in there. So if you are running the 2001+ fuel system you'll need to update that too because the injectors aren't the same.

That?s my mistake. I was told it was from an ?01 but that tune is the one I pulled from the ecu that came with it.

[swizcore]

So when I shift manually the trans is great, no slipping or odd noises. Does this point toward solely the speed input sensors or could it still be something else?

To be specific, when in D and applying normal gradual throttle, it shifts to second at about 100? and then third nearly instantly.

Also, I have Dakota Digital RTX gauges which makes calibrating speedo dead simple but I?m also thinking maybe is a hinderance to tracking this problem down.

[swizcore]

Just had a thought... if I got my front and rear speed sensor plugs reversed, would this issue be a possible result?

[swizcore]

Scratch that thought, they are plugged in correctly.

I can?t get a useful scan. I?ve had this recurring issue where the scanner stops recording or showing any live data beyond about 3 seconds after initiating ?Record? 🤬

[dhoagland]

Hmmmm...

I'm wondering about Force motor current/duty cycle, Input/Output/Speed sensors, ETC... For the Trans part...
Then TPS, RPM, MAF, MAP, on the engine side.

Beyond that maybe time to plug hydraulic gauges into the Trans and see...
I'm not 4L80 expert. More familiar with early 48RE on Dodge side where you measured Governor/Throttle pressure in this situation. But I'm sure they are similar and might give a clue where to look on the electronic control side