New Member, Long time Toyo car owner, First Taco. Whoa! Suprise on interstate with radical downshift

Live in rural area Alabama coastal plain, local speed limits like 45-55, interstates mostly flat.
6/23/16 bought Silver SR5 Double Cab V-6 4x2 6 speed auto. Immediately noticed trans "hunting" for a gear in 45-50 mph range. I adapted by being a bit more aggressive in accelerating to speed, but trouble continued
I took trip from coast to Bham on I-65 starting with 300 miles on truck. Trip is 250 miles and I-65 develops some grades leaving the coast.

I found that when in cruise control at 75 mph on level stretches of I-65, the engine ran at 1900 RPM. To pass a vehicle, I could apply the accelerator by gentle foot pressure and the truck would move smoothly to 2200 RPM and get around the vehicle at around 80 MPH, then let up on the accelerator and return to 75.

Whenever I ran into slight grades, 5 degrees or less, in cruise control the cruise would initially shift smoothly and RPM would increase to 2200. If the grade continued, or got steeper, the cruise would radically and roughly shift to a lower gear(3? 4?) and jump to 3400+ RPM to maintain 75 MPH. This shift to 3400 made the engine extremely loud and annoying, disrupts the driving experience, and is not something I have experienced with any other vehicle I have driven, including other Toyota products (2003 Avalon and current 2014 Venza) with V-6’s and 3.5 liters. The Tacoma is sold as 278 HP and 265 ft lbs torque and I do not expect such a radical downshift to maintain speed with that type of power available.

The manual talks about ECT power(?) that can be activated, but is not very helpful in terms of what actually goes on with the ECT engaged. I hope casual driving would not require constantly engaging and disengaging this feature, if it helps the situation I described above at all.

I will continue to drive the truck for a few days to see what helps the situation, but if it continues (which I expect it will) I will bring the truck in for a check out.

I just joined forum today and learned about TSB SB 0077-16 to ECM Calibration Shift enhancements and will have this to discuss with dealer.

FORUM QUESTION:
Has anyone had similar problems and the TSB fix and does it fix the issue?

 

Welcome to the club of TW!Do some research in the 3rd gen.section of the forum or start a thread in regards to your issues!You'll get more attention!Good luck!

 

Welcome to TW!!

 

Thanks for welcome and advice. New to this. Have found lots of info on issue in 3rd gen forums, Not sure how to start a thread though.

 

Welcome!

 

Welcome! Head over to the 3rd gen section, you'll find a thread with the tranny tsb results.