Transmission Downshifts while going down a grade

This is normal. My '06 Taco and my father-in-law's '06 Tundra both do it. These trucks have computer-controlled engine braking. I'm pretty sure it's described in the owners manual. It was discussed in this thread:

http://www.tundrasolutions.com/forums/tacoma/86260-i-need-gears-101-a/

I think with time you'll learn to like it. It makes it so you can tap the brakes to get down to 42mph in a 35 zone, and the engine brake will keep it at 42 the whole way down the hill without any need to hit the brakes again. It's a fantastic feature, IMO.

jpsmith said:

I think with time you'll learn to like it. It makes it so you can tap the brakes to get down to 42mph in a 35 zone, and the engine brake will keep it at 42 the whole way down the hill without any need to hit the brakes again. It's a fantastic feature, IMO.

Click to expand...

The only part I don't like is a long, slow, downhill freeway onramp where I'm purposesly accelerating to get up to highway speeds and the autobox is staying in a lower gear and I'm turning all kinds or rpm's (for nothing). It would be nice if this feature was selectable or defeatable with a button on the dash, etc.

It shouldn't be engine braking if you're accelerating. You enable it by tapping your brakes. Once you accelerate again, it stops engine braking. If you have it in D, it doesn't like to engine brake much; It constantly tries to maintain low RPMs. If you put it in 4, it's much more likely to engine brake, even without hitting the brakes.

jpsmith said:

It shouldn't be engine braking if you're accelerating. You enable it by tapping your brakes. Once you accelerate again, it stops engine braking. If you have it in D, it doesn't like to engine brake much; It constantly tries to maintain low RPMs. If you put it in 4, it's much more likely to engine brake, even without hitting the brakes.

Click to expand...

Interesting. This is a Tundra (assume the logic is the same though). I typically lightly brake depending how much speed I pickup coming down the hill because the on-ramp turns 90 degrees to the right. Then I get on the gas (lightly) coming out of the turn, but it doesn't shift up until I get on level ground or the rpm's get fairly high.

I read someone mentioned tapping the OD button a couple of times - think I'll try that as an experiment. It's no big deal, but coming from a 5 spd car, this autobox is a different experience...

Oh, you have an OD button? The Tacoma doesn't. In the Tacoma, you have L, 2, 3, 4, and D. If you're in D, it will use OD if it needs it.

jpsmith said:

Oh, you have an OD button? The Tacoma doesn't. In the Tacoma, you have L, 2, 3, 4, and D. If you're in D, it will use OD if it needs it.

Click to expand...

In the Tundra (1st Gen) it's 2,3 D. It's a 5-spd auto.

It defaults to OD when in D, and you can override with the button on the end of the stalk. And at the other end, it defaults to 2**, unless you are under 25mph, then there's a button on the dash by the radio for ultra low (I guess 1st gear).

A 6-speed manual might me easier...

**I don't know if it starts out at 2 from a dead stop or actually starts in 1st.

Mine does the same thing. I will not drive in overdrive around town, it will drive you nuts.

I have a small series of hills by my place and can count on this evey day.

Jonnie said:

......It would be nice if this feature was selectable or defeatable with a button on the dash, etc.

Click to expand...

toyota makes that.......it's a manual tranny.