4l80e time for a new one

[GenBiltstein]

Our TPS is actually the accelerator pedal with 3 sensors, and it only needs two to be working correctly. And the computer knows if those are out of whack usually if they arent agreeing. You cannot adjust them.

Agreed.

The tranny main line pressure is set from that pedal position (%TPS), and speed (MPH).

Agreed again.
This pressure adjustment we are talking about is sometimes referred as governed pressure because of vehicle speed

(MPH)

as the vehicle speed is sensed.

The Throttle position sensor sends TP signal to the computer. The pressure adjusted at the PCS solenoid is not completely performed from the TPS.

PCS amperage should always be compared to line pressure from the pressure port as part of troubleshooting.
TPS or APP position should always be checked against PCS amperage.

The scanner can show what the desired is and you can compare to gauge, and scanner can even set it higher to make sure it will actually change with desired settings.

Agreed.

Good information.

 

[dangerousdave]

Can the scanner set the shift points under WOT?

 

[ak diesel driver]

I believe it requires a reflash

 

[bk95td]

Here's a couple of tranny parts places http://www.bulkpart.com/Merchant2/merchant.mvc?Screen=CTGY&Store_Code=2&Category_Code=4L80E http://www.electricaladvantage.net/4l80esolenoidmasterkitwinternalharness.aspx

 

[GenBiltstein]

Reflashes are common and commonly done at the dealer. I would recommend just the dealer.
Yes you can adjust the shift points however talk to the dealer about it.
As quoted from Buddy. I can definitely vouch for what he is saying.

A PCM reflash can cause more slip if the fuel curve is modified so that less pedal gives you more fuel, because then your going faster with less tranny pressure. Or if the fuel curve does not drop as fast of a rate as the stock one did. A PCM reflash can help if the builder takes this all into account, drops fuel faster, doesnt increase fuel rates at low pedal percentages, or increases tranny line pressure at low pedal percentages.

Other things PCM reflashers should be doing, but I havent seen specifially is lowering the top kickdown speeds, and increasing the kickdown pedal percentage needed. this way you are more likely to maintain OD. They can also lower the downshift speeds, so it wont downshift unless you put the pedal in more. This would make the system just work better rather than needing a TCC lockup mod.

 

[buddy]

In order to get firmer than stock shifting or change shift points youd have to use an aftermarket PCM. Walking J caters to customizations, so you can tell them exactly what you want. A whole new PCM program is loaded that has different parameters, point being you cant just hook something up and adjust one parameter, you reload the whole program. Its pretty easy to do for someone with the right software and equipment.