Why is TCC not locking up on this?

[GrannySShifting]

I don't think this is the same but I will mention it just in case is sparks something: I suspect HPT is only capable of locking the converter if specific variables are met. For example: I tried to lock the converter (on a PO1 PCM) that was calibrated to only lock up in 4th. I was in 3rd at a low throttle angle and pressed the TCC lock button in HPT and the convertor would not lock. I did not test this theory any further and dismissed it at the time as I knew the TCC was functioning correctly with the current calibration to lock up in 4th above 50 mph and below 40 percent throttle angle.

I know this is a GEN 4 forum but another piece to note: In my PO1's, the Shift Lock Enable does nothing whether it is enabled or not. I read on this site that some of the PCM's got the button in HPT but there is no function to it.

That is because HPTuners effed up their software years ago, and sometimes the button logic now is reversed on the P01/P59s If you hit UNLOCK they lock, and vice versa. Theres two "lock buttons" and one is currently reversed and other works as normal. The screwed that pooch years ago I told them about it a million times but they do not give AF about their customers LOL

[GrannySShifting]

Is this the 09 G8 correct vin?

Yes, far as I know, its a 2009 G8 and PCM

[RDF1]

Ive got a buddy with a 08 G8 that i can test with. yOur trying to lock TCC in 3rd gear only?

[GrannySShifting]

in 3rd gear and up, 27mph up at ALL throttle positions. Usually works fine, this car not so much for reasons unknown

[edcmat-l1]

The shitty single disc TCCs in the 6 speed autos need a shit load of apply pressure to keep them locked solid like in the 4 speed autos. The single discs aren't designed to slip like the multi discs are. I do not like using single disc converters in the 6 speeds. I'll tune one but if I'm building the car it's getting a multi disc.

[edcmat-l1]

TCC ramp.jpg

This is your problem. You're still applying pressure as if it's designed to slip. You need to make this table 140 across the board. It needs to apply a consistent pressure.

[GrannySShifting]

Ed it is not commanding it to lock with low pressures in the 20psi or something, it is applying 105psi, locking it fully then COMMANDING it to unlock give it 0psi pressure and then you see the slip occur

Look at the newflash log I posted yesterday. Locked and when TPS gets to 75 or 80% it commands it to unlock. Stays locked with little to no slip until that point


Yes, a single disc has no business in a 6L - but I didnt build this thing.

[edcmat-l1]

I'd set that table to 140 and see what it does.

[04silverado6.0]

TCC ramp.jpg

This is your problem. You're still applying pressure as if it's designed to slip. You need to make this table 140 across the board. It needs to apply a consistent pressure.

That isnt how that table works. That is the rate of apply pressure not the amount of apply pressure. Gen 3 p59 have a apply ramp table not defined in hpt as well. The apply ramp probably should be raised and also could add a small amount to the max pressure if desired, still not the issue here.

[blindsquirrel]

Does it still have the current P0106 as in the logfile in post #1?

[GrannySShifting]

Nope

[GrannySShifting]

That isnt how that table works. That is the rate of apply pressure not the amount of apply pressure. Gen 3 p59 have a apply ramp table not defined in hpt as well. The apply ramp probably should be raised and also could add a small amount to the max pressure if desired, still not the issue here.

That is my understanding as well

[mikez71]

We cant see brake switch status in these can we?

High Speed lock values are from a GM dealer reflash from stock. Just did that yesterday trying to see if file was corrupted or something

Gotcha, guess your high speed lock is different than my tahoe.

I did find a brake pedal channel under systems -> brakes -> brake pedal
It's a stretch, but I have read about bad brake switches de-activating cruise control..

[ns158sl]

I mean for Ed's sake, you could try it to see what happened, but I am sure there is a lot more TCC tables in the bowels of the TCM. Hjtrbo went to the extremes to find the TCC tables he needed. Looked like there is a TON of TCC logic that HPT barely touches on.

[edcmat-l1]

That isnt how that table works. That is the rate of apply pressure not the amount of apply pressure. Gen 3 p59 have a apply ramp table not defined in hpt as well. The apply ramp probably should be raised and also could add a small amount to the max pressure if desired, still not the issue here.

Sounds like you know about as much about this subject as getting a P59 to return to idle correctly.

[04silverado6.0]

Sounds like you know about as much about this subject as getting a P59 to return to idle correctly.

Its literally a "apply ramp" not a pressure map. Here is the table in a p59, looks similar.

[enmanuelpimentell]

Try change your "apply/release" table pattern B. It is in stock form and it doesn't command the car to lock it. Maybe when you get at WOT it enters in pattern B logic.Screenshot 2024-12-07 203557.png

[edcmat-l1]

Its literally a "apply ramp" not a pressure map. Here is the table in a p59, looks similar.

If you install a single disc higher stall converter and do NOT flatten that table, it will literally never lock up solid. Period.

I love it when guys who have tuned 1 or 2 vehicles try to school someone who's tuned thousands. I'd bet you've never tuned a T43 with a single disc high stall converter. First one I did was over 15 years ago now. I've done many of them. Even higher stall multi discs like Circle D, if you don't either flatten that table or increase it drastically starting at zero RPM, it'll flare and catch, flare and catch. It'll drive like shit if that table is left stock.

[04silverado6.0]

Ed, i never said not to raise the table. I have not had a single disc stall in a 6l come in either. That table defines the rate of pressure rise during lockup or a slip condition. The regulator settings will be the initial lockup pressure total after ramp in is complete. If your regulator pressure is 30 then setting the ramp to a value of 30+ is going to give full pressure at an instant.

[GrannySShifting]

Now that we got that out of the way, any ideas? Doing all that the car still wont lock up unless you use bi directional controls LOL