Looking for some 6T75 help

[riverside21]

2012 acadia bgg trans tune 4 no slip 5 and 6 full interp.hpt

2012 gmc Acadia with all the usual tcc shudder issues. The tune I attached is working the best of all the ones I've done so far, but still having some issues with 5 & 6 leaving tcc lockup. I left the stock apply/release and desired pressure table. I added some increases to the apply ramp and zeroed out slip in 5/6. The problem I mostly get is a somewhat harsh tcc engagement in 5th at low rpm and an occasional strange feeling of a sudden drop coming out of 6th to 5th on an incline under light load. Under load seems fine and no fluctuating tach at highway speeds like original tune.

Any suggestions?

[ltemup4650]

What do you mean by "drop"? Do you mean a harshness or a jerk?

[Russ K]

Try these TCC settings.

Russ Kemp

[riverside21]

Yes, like a pause then suddering downshift until power comes back or it hits 4th gear.

[riverside21]

Thanks for the file Russ K! I see you altered the desired pressures and left the ramp stock. You also set 5 & 6 apply/release at 43/40. I will load this and give it a try. One thing that perplexes me is the tcc adapt row where torque min is 22 ft/lb.....but torque max is 15 ft/lb. These are the stock settings and I see you left them alone. These settings to my mind seem like they cancel each other out?

[riverside21]

So I'm still having trouble with this vehicle and adjusting the tune. After doing some graphing and reviewing in vmscanner what's going on is that in 5th or 6th under a light throttle at cruising speed when encountering a load like a gradual uphill, the tcc line pressure drops off and a huge slip occurs. The tcc line pressure then tries to ramp back up and lock everything down - which usually occurs if throttle is backed off or the incline levels out. Seems like there is a table or some other parameter coming into play that's knocking down the tcc apply pressure at those times of engine load. Any clues??

[Russ K]

Try these TCC changes. Do you have any misfire DTC's?

Russ Kemp

[riverside21]

Thanks Russ, I'll try it!

I have no misfire dtc's present.

[riverside21]

Can someone take a look at my scan file. This particular one is a quick scan in 6th with tcc locked. My tcc line pressure dips to zero and massive slip occurs. Any ideas are welcomed.

[riverside21]

Still experiencing frustrations with trying to leave 5th & 6th tcc lock in place. Problems are occurring with steady/light throttle at cruising speeds then encountering a slight load or applying a bit more throttle. When looking at logs and going off the driving feel, it seems to me like the car is on a threshold of a downshift, so something tells the tcc to unlock....but then instead of a shift it just lugs and tcc engages again. This is giving me slips and bangs with a log graph that shows zero tcc line pressure at those spikes. I've fiddled with some shift parameters but didn't notice any difference so I returned those settings. This vehicle is using the #24261871 O.S.....and I thought i read somewhere there was an issue with it.

Any thoughts?

[tooter1]

I have a '12 Enclave AWD and am trying to eliminate a shudder. I did three drains and fills and added the Lubegard shudder fix on the last fill. Hopefully, I can get this to go away with a tune.

[riverside21]

So....I'm one of the lucky ones that has a bad torque converter and no amount of tune is going to fix. I currently have it disabled in all gears until I can change it, and I'm just avoiding highway speeds. If I had to guess mine is probably warped and/or missing the lining. If I try leaving 5th & 6th engaged it pulls down the engine rpm then slips/catches in an annoying fashion. VCM scanner shows spikes everywhere during the slips. In the meantime I added a trans cooler - which will also be helpful after the repair.

[tooter1]

So....I'm one of the lucky ones that has a bad torque converter and no amount of tune is going to fix. I currently have it disabled in all gears until I can change it, and I'm just avoiding highway speeds. If I had to guess mine is probably warped and/or missing the lining. If I try leaving 5th & 6th engaged it pulls down the engine rpm then slips/catches in an annoying fashion. VCM scanner shows spikes everywhere during the slips. In the meantime I added a trans cooler - which will also be helpful after the repair.

Sorry to hear that, that sucks! Hopefully, I won't have to replace my TC, but I will if I have to.

[tooter1]

I copied what Russ put in his first hpt file and mine is doing pretty good. I can still get some shudder in 5th but, I don't feel it in 6th.

Wondering if I should change the 5th gear too.

[Biggmax81]

Try these TCC changes. Do you have any misfire DTC's?

Russ Kemp

Will this file work for an 08 Acadia AWD?