Looking for someone that tunes with HP Tuners in the Nashville TN area. I have a GMC Acadia and would like to go in and turn off the torque converter lock-up in 2nd, 3rd and 4th gear.

I can’t help but am curious why? Just curious

I'm assuming GM had the converter lock up in every gear but 1rst for fuel mileage reasons. Where I live with hills and curves, the thing is always hunting a gear to the point that every once in a while it will start to shudder. It does great when I put it in manual mode and shift it myself. By the time it gets to 45 mph it's in 6th gear regardless if it's on level ground or going up a hill. I read on the Acadia forum that if you had HP Tuners you could control everything about the shift parameters and mock-up.

Interesting. I have been interested in getting an hp tuner. They are kinda spendy for the credits for each vehicle.

From what I researched it's around $50 a credit. My GMC takes two credits. $100 to be able to change most anything in the ECU/ TCM is not bad at all. I believe the hand held device is around $300.

Any local performance tuning shop that tunes late model cars SHOULD be offering HPT support.

sounds loike the tranny control module needs a reset to relearn

What is the procedure for a TCM reset/relearn?

I believe the process is to disconnect the battery and open the drivers door. If you don’t open the door, it holds just enough charge to keep the memory. I had an issue similar on my 2015 Sierra with the BCM and this did reset it.

Ymmv

i believe the auto parts stores can reset with the reader they use.also and this will seem extreme but works safelyas i have done it many times,get up to cruise speed in od but only as fast as needed(50)to be in od,pull shift lever to 1(no it wont blow up)let off throttle and coast to a stop.kill motor while tranny is still in 1,move to park and restart.it wont over rev and it does work.tried and proven

the above method was actually in earlier chev manuals

quote:

Originally posted by rusty:
the above method was actually in earlier chev manuals

Let me ask to make sure.. Put the shift selector in "D", Get up to speed so as to be in 6th gear with the torque converter locked up. Then pull the shifter back into "L", which is manual mode, then let off the gas pedal and coast to a stop, turn off the engine by turning the key to the off position, then put the shifter in "P" and restart? Please don't read any sarcasm into this as I am just trying to be thorough as to not damage me or anything else on the vehicle. LOL