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Discussion Starter #1
I've got an 08 rav4 limited. It a 4 wheel drive and I rarely need it because it's so good in the snow. The previous owner says that when the traction control is activated , it changes where the drive wheels are, like it can automatically activate the rear. Is that the way my system works? It would explain why I rarely need to put it in 4 wheel drive myself if it is.

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Yes, the 4WD ECM sends a variable % of power to the rear wheels as sensed by the car's accelerometers and wheel speeds. It works so seamlessly that it's operation is virtually transparent to the driver.
The 4WD dash light is an error light. It should never come on. It will if a wheel speed (ABS) sensor fails or if the system overheats.
 

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I've got an 08 rav4 limited. It a 4 wheel drive and I rarely need it because it's so good in the snow.
I assume you are saying that you have not needed 4WD because you never had the need to push the 4WD button on the dashboard.

If you have been driving around New Brunswick over the last week, you can be certain that you have indeed been using 4WD.

Under normal road conditions, the RAV4 send all of the engine torque to the front wheels, and also turns a driveshaft which is connected to the rear differential (axle) via a clutch. When the clutch is not engaged, no torque is applied to the rear wheels.

When the wheel speed sensors determine that the front wheels are rotating faster than the rear wheels (i.e. the front tires are spinning), the computer sends a signal to engage the clutch at the rear of the car, and engine torque is then applied to the rear wheels.

As Dr. Dyno said the, the ECM can send a variable % of power to the rear wheels as required by various conditions. And as the Dr. says "It works so seamlessly that it's operation is virtually transparent to the driver." That is why you may think that you have not been using 4WD.

The button on the dash will engage the rear wheels immediately without waiting for the front wheels to spin. The only time I ever used this feature was when climbing steep hills (either dirt or ice and snow). In situations like this it is important to keep up your forward momentum. If the front wheels were to spin for just a second, the momentum would be lost and even with the help of the rear wheels it might be difficult to regain traction. This manual mode will automatically return to automatic mode when your speed reaches 40 kph.
 

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Moved to 4.3 Mechanical.

Actually, with an LED connected to the rear clutch signal out of the 4WD ECM, I see that the rear drive is at least partially engaged on takeoff even on dry pavement. So, under those conditions, it is engaging until it determines the front wheels are not slipping.
 

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Is it possible the my "Smart" AWD system got dropped on it's head when it was a baby? I like most things about my Rav but it definitely does not send much if any of the power to the rear wheels unless I press the lock button, and it is annoying to try to remember to do that at pretty much every intersection. (I live in Anchorage, AK, and it has been a snowy winter.) Toyota could have at least put the button on the steering wheel!

Further evidence (I think) that not much power makes it to the rear wheels is that when driving in situations where there is low traction and increased resistance, the pull right or left on the steering wheel from whichever front tire has better traction is quite pronounced. Maybe not as pronounced as on a front wheel drive car, but I don't notice any pull at all from my Outback or my AWD ford Flex. The driving conditions I am trying to describe here are driving through snow that used to be fairly deep, but has been driven on for a day or several and it stayed cold and now the snow is more like several inches of slippery grey sugar and the car has to churn through it a bit until you get going.

I've lurked enough here to know that you (Dr. Dyno) understand this car far better than I do, but I have been trying to match my experience with what Toyota says it is supposed to do, and mine sure doesn't seem to automatically engage the rear wheels when starting from a stop to prevent wheelspin or at least not enough to make a difference. It does seem to apply some power to the rear wheels to minimise wheelspin if a front wheel starts spinning, but not enough to keep the front wheels from tugging on the steering wheel, and it definitely acts more reactive than proactive. Even on dry pavement (with studded tires, so less than ideal traction) if I am not careful, I sometimes get a half a tire rotation only from a front tire and totally unintentionally. By default I'm pretty gentle on the gas pedal, too. There is no way my Outback would do that on dry pavement unless I really, REALLY meant to do it.

Is it possible that only the cool kids with the V6 or the Sport/Limited package get the Smart version of the AWD? Or maybe my 2010 predates the features that I keep reading about? I don't have the 2wd version, but other than that, mine is pretty basic.
 

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The Outback is a permanently engaged all wheel drive system with no driver intervention required. The RAV is an on demand all wheel drive system engaged by the computer (or the button) as required. These are two entirely different systems.
 

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Well jerak, you hit on two of my top loves, Alaska and my 4WD RAV4! And WELCOME to the forum. We have several Alaskan members and they may chime in. My BIL lives in Slana and IS the reason I have our RAV4. After test driving a V6 4WD for him in CT I HAD to have one. (We bought his in RI and he drove it home to AK.) Just a few minutes into that test drive we had to start off from a red light on a winter sanded uphill. I didn't floor it but was surprised at no wheelspin.
When I first got ours full throttle V6 takeoffs would give a chirp from the front wheels on dry pavement but that soon disappeared. It must have learned I know how to use the pedal on the right. If I launch it on dirt or grass it leaves four spin marks. And that's w/o using the 4WD LOCK button.
So maybe you baby yours too much or it came as a baby with the low end of the 4WD IQ spectrum. :roll: :doh: :wink:
 

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In my experience, the traction control and 4WD really show up with the V6 and aggressive driving. Our roads get quite sandy and a launch will spin all four, but not for long as the traction digs in. During a turn and suddenly hitting sand, the RAV4 will lurch into correction.
 

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Discussion Starter #10
thanks for the replies guys!

Yes I did mean that I just never needed to push the 4 wheel drive button ,although I do try it sometimes at stop lights so I can accelerate out of the gate leaving the other fellas spinning away! :)
I think my Rav has great traction , the system works well. I didn't realize that the system engages the rear wheels automatically. I'm amazed at how much snow I can actually go through being the rav is so low to the ground.
One flaw is that I wish I could turn off the traction control without doing the backyard E brake and regular brake dance. As Rickl mentioned, the momentum is easily lost when trying to accelerate say up my long driveway when there is a few feet and up ,of drifted snow. I end up going slower and slower then have to stop, reverse and try again. I can only dream of having a V-6 , the 4 banger is barely worthy! :)

Thanks again guys.....
 

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Is it possible the my "Smart" AWD system got dropped on it's head when it was a baby? I like most things about my Rav but it definitely does not send much if any of the power to the rear wheels unless I press the lock button, and it is annoying to try to remember to do that at pretty much every intersection. (I live in Anchorage, AK, and it has been a snowy winter.) Toyota could have at least put the button on the steering wheel!

Further evidence (I think) that not much power makes it to the rear wheels is that when driving in situations where there is low traction and increased resistance, the pull right or left on the steering wheel from whichever front tire has better traction is quite pronounced. Maybe not as pronounced as on a front wheel drive car, but I don't notice any pull at all from my Outback or my AWD ford Flex. The driving conditions I am trying to describe here are driving through snow that used to be fairly deep, but has been driven on for a day or several and it stayed cold and now the snow is more like several inches of slippery grey sugar and the car has to churn through it a bit until you get going.

I've lurked enough here to know that you (Dr. Dyno) understand this car far better than I do, but I have been trying to match my experience with what Toyota says it is supposed to do, and mine sure doesn't seem to automatically engage the rear wheels when starting from a stop to prevent wheelspin or at least not enough to make a difference. It does seem to apply some power to the rear wheels to minimise wheelspin if a front wheel starts spinning, but not enough to keep the front wheels from tugging on the steering wheel, and it definitely acts more reactive than proactive. Even on dry pavement (with studded tires, so less than ideal traction) if I am not careful, I sometimes get a half a tire rotation only from a front tire and totally unintentionally. By default I'm pretty gentle on the gas pedal, too. There is no way my Outback would do that on dry pavement unless I really, REALLY meant to do it.

Is it possible that only the cool kids with the V6 or the Sport/Limited package get the Smart version of the AWD? Or maybe my 2010 predates the features that I keep reading about? I don't have the 2wd version, but other than that, mine is pretty basic.
You either have a problem with your rav or you have crappy tires. These things are great in the snow and other crappy weather. All the 4 wheel drive systems are the same among the trim levels so that would not be the issue. If
I remember there was a warranty extension of the rear clutch coupler. That going bad would cause power to not reach the rear wheels, perhaps you need to get it in to a shop and have it looked at.
 

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One flaw is that I wish I could turn off the traction control without doing the backyard E brake and regular brake dance. As Rickl mentioned, the momentum is easily lost when trying to accelerate say up my long driveway when there is a few feet and up ,of drifted snow. I end up going slower and slower then have to stop, reverse and try again. I can only dream of having a V-6 , the 4 banger is barely worthy!
In this case, it's not an issue of I4 vs. raw V6 power. If you don't do the 'tap dance' ritual you mentioned (for models 2008 and prior), either engine will bog down if the TRAC/VSC is engaged as it detects wheels slipping. It is a pretty rare event, but there are times like your steep driveway, or battling your way out of a snow-crusted intersection, where you want the power. Of course, it all starts with good tires...If they are getting a good bite and not slipping, no loss of power.

The addition of a single button to push to temporarily disengage that traction control is one of the best features starting in all 2009 RAVs, a blessing for folks in snow country. But I'd venture to say most RAV owners don't know how to use this. It is counter-intuitive to have to turn something OFF in order to get more power!
 

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You either have a problem with your RAV or you have crappy tires. These things are great in the snow and other crappy weather. All the 4 wheel drive systems are the same among the trim levels so that would not be the issue. If I remember there was a warranty extension of the rear clutch coupler. That going bad would cause power to not reach the rear wheels, perhaps you need to get it in to a shop and have it looked at.
Agreed. As described jerak's RAV4 isn't operating as designed.

In this case, it's not an issue of I4 vs. raw V6 power. If you don't do the 'tap dance' ritual you mentioned (for models 2008 and prior), either engine will bog down if the TRAC/VSC is engaged as it detects wheels slipping. It is a pretty rare event, but there are times like your steep driveway, or battling your way out of a snow-crusted intersection, where you want the power. Of course, it all starts with good tires...If they are getting a good bite and not slipping, no loss of power.
I saw both sides of this with our foot of snow yesterday. On a quick trip to the grocery store for some hot chocolate makings I crossed our not well plowed CT route 2 at a traffic light from the side street I live on. Its a big wide five lane intersection with plenty of room for some fun. With the other cars driving cautiously I floored it when the light turned green. Humble me :shrug: put on a show of the RAV4 4WD and V6s capabilities. Literally shot across the intersection in front of the audience waiting at the lights. Accompanied of course with some sliding and VSC beeping. I wonder what both front and rear wheels spinning looked like to them. Repeat performance in the opposite direction on the way home for those that missed it.

A little earlier I'd backed the RAV4 onto into the foot of snow on my yard to get it out of the way while I plowed. While heading out on the trip above the car went forward but stopped when it hit the ridge the plow had left at the edge of the yard. All kinds of beeping but no throttle response, the same thing I remembered from my extensive deep snow testing years ago. When the car stops moving the ECM sees no reason the apply power to spin the wheels. Solution back up and use a little more pedal to break thru. (Then proceed to the test at the intersection above just to make sure everything's still okay. :wink:)
 

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Sounds great, it's fun and educational to put the pedal to metal in the snow! We've had a record-breaking winter here and plenty of times to see what the RedRAVer could do. For me it was a big lesson in tires. After 3 really mild winters, I had been getting by with all-season Continentals. But with tread half gone, it was time to go dedicated winter Nokians. Such a difference, a completely different vehicle.

By comparison, my friend has a RAV AWD 2011 with crappy all-season Yokos with only 3/32-in tread remaining. She came over to go skiing with us and got stuck 3 times--once in front of my house where I'd been easily driving with my snow tires. Tried to explain using the TRAC OFF button, but I don't think it sunk in. She did comprehend the AWD LOCK button, and that helps some. Driving up the ski hill I showed off the acceleration and the braking. She couldn't believe the difference. (I couldn't believe she was running with those near-bald tires!)

...All kinds of beeping but no throttle response, the same thing I remembered from my extensive deep snow testing years ago. When the car stops moving the ECM sees no reason the apply power to spin the wheels. Solution back up and use a little more pedal to break thru...
Thus the nicety of the "TRAC OFF" button in the 2009+ models. There are work-arounds possible like backing up and making another run, as the OP did on his steep driveway. But with the TRAC and VSC easily and temporarily shut off (and excellent tires) there is maximum get up and go from a stop especially in deep crud snow.
 

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By comparison, my friend has a RAV AWD 2011 with crappy all-season Yokos with only 3/32-in tread remaining. She came over to go skiing with us and got stuck 3 times--once in front of my house where I'd been easily driving with my snow tires. Tried to explain using the TRAC OFF button, but I don't think it sunk in. She did comprehend the AWD LOCK button, and that helps some. Driving up the ski hill I showed off the acceleration and the braking. She couldn't believe the difference. (I couldn't believe she was running with those near-bald tires!)
Yeah, and her biggest problem is stopping not going. Hope it doesn't bite her some day.


Thus the nicety of the "TRAC OFF" button in the 2009+ models. There are work-arounds possible like backing up and making another run, as the OP did on his steep driveway. But with the TRAC and VSC easily and temporarily shut off (and excellent tires) there is maximum get up and go from a stop especially in deep crud snow.
Very familiar with that too having used the tap dance many times while testing the limits. What I don't like about turning TRAC off is the very real possibility of doing major damage when spinning tires suddenly hit dry or even wet pavement. It was only a Chevy so it didn't really matter but a friend of mine lunched the transmission that exact way.
 

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Moved to 4.3 Mechanical.

Actually, with an LED connected to the rear clutch signal out of the 4WD ECM, I see that the rear drive is at least partially engaged on takeoff even on dry pavement. So, under those conditions, it is engaging until it determines the front wheels are not slipping.
I test drove a 2016 xle today and discovered a cool feature. There is a setting that shows 4 wheels and small meters that show how much and to what wheels power is going to. I didn't play with it much, but from a stop power was always going to the rear wheels.
 

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Was out having fun with my wife's RAV4 this weekend, we got our first good dump of snow about 16cm of snow in about 8-10hrs on Sunday, had to go drop off the boy at a birthday party a good 15-20min drive away and of course no roads were plowed yet, my wife had gone out earlier and come back just before I left, so she actually suggested I take it over my Corolla because the roads were crap, who am I to say no to that? lol :)

It was fun driving it, I tried both pushing the diff lock and leaving it alone on hard launching and both times I experienced no major slipping, I did get the Traction control to kick in and get paranoid of my sideways driving a few times, beep beep beep beep beep, lol.

I'd definitely buy another RAV4 V6 for myself if I didn't have my eyes set on an IS350, they're a beast.
 

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... I did get the Traction control to kick in and get paranoid of my sideways driving a few times, beep beep beep beep beep, lol.
Yep, much beeping indicates preferred operational mode is being experienced! :twisted: :thumbs_up:
 

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...Very familiar with that too having used the tap dance many times while testing the limits. What I don't like about turning TRAC off is the very real possibility of doing major damage when spinning tires suddenly hit dry or even wet pavement. It was only a Chevy so it didn't really matter but a friend of mine lunched the transmission that exact way...
In reality, the only time I really needed the 'TRAC off' in multiple tests was in deep (endless) snow, so no chance of hitting bare pavement to cause damage. Plus there didn't seem to be a need to gun the engine or spin the wheels with the TRAC off. Heck I didn't even need to rock it back and forth. Once the vehicle is moving, then tap the TRAC button again to turn it on. An elegant solution to being stuck by snow (and the TRAC nanny).
 

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Once the vehicle is moving, then tap the TRAC button again to turn it on. An elegant solution to being stuck by snow (and the TRAC nanny).
Yep, and a great example of understanding how the system works - then using not abusing it.
 
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