Is the transmission in "D"?

 

It depends on the degree of angle, if it's not very steep then the car will maintain the same speed.

 

yes transmission is in D,

Reason why I know is because,

its not like my last car,

and other cars are madly pushing the brakes and i only need to touch it a few times..

Could my front brakes be automatically engaging while downhill?

 

yes transmission is in D,

Could my front brakes be automatically engaging while downhill?

No brakes are engaging, but you might be getting some engine braking, depending on your shift lever position.

If you bring the shift lever straight back from neutral, you are in D. If you slide it to the left from there, you stay in a lower gear will get some engine braking on a downhill and it won't shift as much up or down.

If so, you're not the only one thinking the logical place for D is in the position to the left, as it rests there better. Ahem, me. Doh.

 

I could be crazy, but my transmission (2010 base V6 with 5-speed automatic) appears to downshift into a lower gear if I gently tap the brakes on a long, steady downhill. After removing my foot from the brake pedal it seems to hold the lower gear until I touch the accelerator. I think that might be the behavior you're referring to?

If this is a feature, then I'm quite happy to have it since it helps maintain a steady speed on downhills without using the brakes or manually downshifting (although if the hill is steep then downshifting/braking is obviously still required).

 

If I hold the cruise control lever in the decelerate position, it feels like the car will begin braking on a long down hill.

 

That's right, it does! You can even see the reflection of the brake lights coming on, especially at night.

 

Sounds like you need to get it checked. That is pretty low for previous owner needing brake pads, maybe they are hanging up a bit :shrug: Does your fuel usage seem to be normal overall?

For me, going downhill in D, I need to ride the brakes quite a bit--this on a fairly steep twisty road from a ski hill area. No noticeable engine braking at all. The gear in the left notch (3 in my I4 engine) gives some engine braking.

Maybe someone else has some ideas to troubleshoot the transmission shifts.

 

I'll toss in my 2 cents:

It sounds to me just like engine braking, except with a computer system that makes it smarter than typical (as well as less modern) automatic transmissions. I, too, have noticed that when going down a steady, not particularly steep incline (but one where most other drivers are riding the brakes) I almost never need to brake. As wallaceg mentioned, if, when going downhill and it does shift up, tapping the brake until it downshifts again then releasing appears to somehow tell the computer system that you want it to stay in that gear, until you touch the accelerator. I'm not at all knowledgeable about computer systems in modern cars, but these are just my guesses from what I've experienced. I will also note that, for an automatic, the RAV4 seems to have exceptional engine braking, not only somehow knowing not to shift up a gear when going downhill in drive but also in low gear on a very steep road it doesn't take off any more than a manual 4Runner in 1st gear—quite impressive from what I first expected when transitioning from manual transmission to automatic.

 

Hmm thanks for the 2 cents!


I will try tapping the accelerator next time and see if I speed up.


If this is really engine braking from the transmission I love it!


My crappy ford focus engine braking would freaking red line my car going downhill. Retarded design...

 

Sounds normal to me. There's a whole pdf on how intelligent the rav4 transmission control module is. It takes into account speed, steepness, accelerating vs decelerating, And then it decides which gear to use. Toyota minivans and suv's tend to err on the safer side, downshifting earlier than I'd like. They've been doing this since the 90s.

You're welcome to come and test drive mine if you'd like, for comparison.

Dr J

 

Sounds normal to me. There's a whole pdf on how intelligent the rav4 transmission control module is. It takes into account speed, steepness, accelerating vs decelerating, And then it decides which gear to use. Toyota minivans and suv's tend to err on the safer side, downshifting earlier than I'd like. They've been doing this since the 90s.

Good to know this behavior is normal for Toyotas!

Do you happen to have a link to this pdf regarding the RAV4 transmission control module? I'd appreciate reading more about this, as the specifics of how the computer system decides which gear to use is something I've been very interested in learning about since I first started driving the RAV.

 

Most cars I've had experience with will freewheel in D, i.e. on a long hill will just run away unless you change the shift lever down one gear. I wonder if these newer transmissions can tell when you're on a long down hill and instead of free wheeling, the leave the lock up clutches engaged in order to provide some engine braking, more like a manual?

 

Not exactly sure about your situation, as my wife is the one with the RAV, and it's an '02 with the 4-cylinder engine and 4-speed auto trans.

However, I have an '05 Sienna with a V6 and 5-speed, which, I believe, is the same powertrain that you have. When going down a hill, if you push on the brake just enough to turn the brake light on and the car does not slow down (enough to satisfy the computer), it will downshift. The difference between 5th and 4th gears is not all that much, it's just barely enough to make any kind of difference.

Next time this happens, manually put the selector into 4th gear and listen to see if the engine speeds up. You could also watch the tach, but it might be better to keep your eyes on the road.

.

 

My wife has a 2009 Corolla and it does the same exact thing and my 2010 RAV4 four cylinder as well. Mom we go downhill depending on the grade and speed the transmission downshifts and uses the engine of slow our vehicles down


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Hello. I have a 2010 RAV4 V6 Limited
122k miles and have noticed the same thing...
If this is a feature , it's very cool.
It's as if it detects the downgrade/angle of the road and the tachometer jumps 500 rpms as if I had shifted to a lower gear.
It definitely slow the car down , and when I apply the accelerator, the tachometer drops back down .
I was going to mention to my Toyota service dept. But thought I would come here first. Thanks

 

My RAV will engine brake on a long downhill. If I tap my brakes more than once on a decent, the transmission will downshift one gear and stay there until i depress the gas. It performs the downshift very smoothly.

 

I just noticed it today when going down a sharper declined road than I normally travel at higher posted speed limits?. With my exhaust mods, the downshift and held gear is a little more pronounced.