Problem while accelerating down a hill...auto tran?

There is one specific spot right near my house where my transmission pisses me off. The truck is an 09 dc trd sport.

I am turning off a road and there is not a stop sign. I make a left and increase throttle as I proceed down a slight hill. The problem...the truck is downshifted, the RPMS go up but there is little to no acceleration.

I've mentioned it on here before but no one has ever reported similar issues. Now, I find THIS PAGE OF TACOMA COMPLAINTS and it is reported over and over and over. Read a few of the complaints and you will see what I mean.

My question...is this something the dealer can fix / reprogram? What can be done?

 

maybe a reflash of the computer would help still under warrenty

 

For those too lazy to click on the link...a few excerpts:

 

how many miles are on it?

 

8K but the problem has existed for as long as I can remember.

Bought it new in February.

 

yeah i would have it back at the dealer and have them re-flash everything. most dealers only do the engine or trans or where the problem occured, if you take it back and your as anal as i am i would expect to see proof of the re-flash cause most mechanics are required to put a new re-flash label when they do it

 

What all is involved with a complete reset like that?

How long does it take for the vehicle to "learn" my driving habits? I don't even understand how or why a vehicle learns this stuff anyway.

Is there any danger in doing this?

 

I noticed mine did that a few times (08 trd or) but... after the engine break in I kinda forced the transmission to learn my style by manually shifting for a few weeks, and still do it on occasion (downshifting, from like L-2-3-4 and leave off D for awhile). After doing that, it seems to be extremely responsive to the pedal now compaired to how it was. Downside is fuel econ I guess, but I usually get 17.5-18.5 avg, and I gotz a lead foot. Also I got a truck, not a prius, so millage isn't that big deal for me.

 

Save the trip to the dealer. Undo the battery terminal on your truck for 30 minutes. This will clear the memory state of your ECU; essentially forcing your truck to relearn your driving pattern. There is no harm doing this and your transmission will reconfigure it's shift points.

 

Whats the difference between reflashing and removing the battery terminal for 30 minutes?

Hell, I'll remove it for a couple hours if that is all I have to do! I will also begin shifting through the low gears to try and "teach" it my style. Although I don't think anyone's style would match the way the shitty computer in this truck makes it do.

Who downshifts when trying to accelerate down a hill? Who downshifts randomly while coasting down a hill? I guess someone who likes to hear revs and watch the needle on their tach bounce around.

 

Re-flashing is for when there is a software change for the ECU, and it is loaded via a programmer into the ECU. The battery trick doesn't update anything, rather it just returns your ECU to it's original state. BTW your truck is designed to downshift on a downgrade. Our trucks utilize engine braking downhill to help slow it down and save the brakes. If you want to up-shift downhill, go easy on the gas so the truck will upshift.

 

I'll give it a shot tonight.

As for the downshifting...I know it was designed that way and I hate it. Hate it hate it hate it! I had an 05 Dakota and an 04 Tacoma and neither of those trucks did that. And yet I never went through brakes on either truck. I appreciate their effort to save my a couple $$$ but I'd pay more to get rid of that feature.

And gassing on the downhill does not always work. It actually makes it worse because you from coasting to engine braking (slowing) to a slight acceleration then back to a higher revved engine braking (when it doesn't work). It does it at random times so not even I can predict and brace myself for the speed change.

On some long downhills, a little gas will get the truck to upshift but it downshifts again 10 seconds later. Passengers think I don't know how to control my truck because the inertia is throwing them back and forth.

 

I have similar "issues" with my truck's tranny.

Most cars i've driven don't downshift right away when i depress the accelerator like my Tacoma does... For Example, i'm getting off the freeway so i change lanes onto the off ramp, let go of the gas and i can feel my tranny downshift and start to slow my truck very quickly (compared to other vehicles), rather than coasting until the car slows THEN downshifting. Sucks because if i want to coast it down a hill, i can't because my truck will start to slow down considerably, even when downhill.

Also when accelerating, i notice that sometimes when i press the accelerator, the revs go up, my truck doesn't move much then all of a sudden a shift and a tug. I don't know if it's because i usually have a somewhat heavy foot and this problem iv'e noticed happens mostly when i try and drive calm or ease onto the accelerator.

It's very annoying but i just assumed it's how Tacoma's are since i havent had any tranny problems. MAYBE it's because it's "learned" my heavier footed driving and when i want to take it easy it isn't used to it? Dunno but it sucks big Huevos!

 

I drove on I-76 from Philly to Pittsburgh through all the rolling hills. I would say about 50 miles outside of Lancaster, my truck started to learn what it need to do. Definitely do the battery trick and if that doesn't help take it to the dealer to have the ECU flashed. That way Toyota will see a reported problem and possilby come up with a software update for the transmission. Sorry to hear your truck is having issues. I know Pittsburgh is hilly, and having your problem is very agitating. I wish our trucks had a button on the shifter for "tow mode" and "normal" that way the truck wouldn't be so eager to downshift.

 

At higher speeds, the downshifting is not very noticeable. When it shifts from 3rd to 2nd on a local backroad, it will catch your attention. It has done it so hard, my wife has had to catch herself on the dashboard because she was caught off guard.

It sucks to not have control over it. Makes me wish I had a manual.

 

Ditto

 

Got an appointment on Monday to have the vehicle re-flashed.

He also said it was driven by the sales manager who is very light on the pedal. I am a lead foot!

We'll see....
Thanks again for the idea of re-flashing the computer.

 

Does the re-flashing really work?

Both of our trucks do this and we can't stand it.

 

Did you buy your truck brand new (no miles)? If so, probably not.

I don't expect it to help my situation much but I never knew re-flashing could be done. I bought my truck with a couple thousand dealer miles on it and it may have learned that drivers style.

The engine braking is just something we have to live with. When I'm there on Monday, I'm going to ask if there is any reprogramming that can be done to eliminate it. My dealer is pretty awesome at helping me out.




2 Tacoma's....You lucky bastard!

 

Definitely let us know how it goes..