How do the Toyota RAV4 all-wheel drive systems work?

Toyota RAV4 driving off-road

From its introduction in 1994, the Toyota RAV4 was never designed to compete with the off-road capabilities of its Hilux and Land Cruiser siblings. The model name is a contraction of Recreational Active Vehicle with four-wheel drive – a description that identifies the RAV4 as a lifestyle vehicle with the additional benefit of some all-wheel drive performance.

To dismiss the fourth-generation Toyota RAV4 as an urban-only SUV undersells the sophistication of its chassis. Its ability off the beaten track comes courtesy of two different optional all-wheel drive systems designed to keep you safe, under control and mobile in conditions that would likely be impossible in a traditional car.

Let’s take a closer look at these two systems. We begin with the most popular E-Four electronic system found in all-wheel drive RAV4 Hybrid models, followed by the mechanical system found in traditional all-wheel drive petrol and diesel models.

Toyota RAV4 Hybrid E-Four all-wheel drive

In addition to the familiar Toyota Hybrid engine and motor powering the front wheels, models with E-Four all-wheel drive employ a second, rear-mounted electric motor to power the rear wheels. This allows torque to be distributed between all four wheels, improving grip and stability.

In normal driving, all of the car’s power is sent through the front wheels as this is the most fuel-efficient use of the energy. The RAV4’s electronic control unit constantly monitors data such as vehicle speed, accelerator angle and wheel speed to calculate the optimal spread of torque. If it detects a need for more torque at the rear (such as if the front wheels are slipping), it instructs the rear motor to send a precise level of torque to the rear wheels to make up the shortfall.

Up to 60% of the car’s total power can be sent to the rear axle. So when you’re pulling away, going up a hill or driving on a low-traction surface, having a measure of torque delivered to the rear wheels makes it easier to set off in a controlled manner. The E-Four system can also shuffle torque delivery across both axles to deliver a sportier, more assured driving experience.

Toyota RAV4 Hybrid tows a trailer off-road

Towing capacity more than doubles if you opt for a RAV4 Hybrid with E-Four all-wheel drive. Front-wheel drive models can tow up to 800kg but models with E-Four all-wheel drive can tow 1,650kg.

Toyota RAV4 mechanical all-wheel drive

The fourth-generation RAV4 features a programme that co-ordinates every function of the four-wheel drive system, stability control system and electric power steering. Compared with the all-wheel drive setup in the third-generation RAV4, this new management system does not always need to rely on slip detection before deciding on the distribution of torque to each wheel.

Toyota RAV4 Hybrid drives along gravel lane

The driver has the option to come out of this default setting and increase the level of the system’s interaction by engaging Sport mode, activated by a button in the centre console. Like a heightened level of awareness, this mode sends data to the relevant ECU from sensors monitoring vehicle speed, steering angle, throttle input and yaw rate, which the programme then uses to determine the proportion of torque to send to the rear wheels.

Toyota RAV4 4-wheel-drive 1

This is physically actioned by varying the strength of electric current heading into an electro-magnetic solenoid in the control coupling located ahead of the rear differential (see image above). Depending on driving conditions, the amount of torque being directed into the differential can vary by as much as 50%, from the car being entirely front-wheel drive for optimum fuel efficiency to an equal sharing of torque between the two axles.

Four-wheel drive system Toyota RAV4

So accurate is the monitoring of vehicle behaviour that the shuffle of torque between the axles will have already started before any slip or understeer is detected. From the moment the steering is turned, the system automatically adjusts to a 90:10 front/rear torque distribution, priming the car to deliver optimal cornering poise and grip. This simultaneously reduces the load on the front wheels and the likelihood of experiencing understeer.

Should the cornering force go on to exceed the car’s adhesion to the road surface, however, yaw rate controls react within milliseconds to instruct the system to apply up to 50% of the available torque to the rear wheels to improve grip.

Four-wheel drive system Toyota RAV4
RAV4-AWD-05

There are times, such as in snow or on steep gravel tracks, when the driver will know before even setting off that grip levels will be poor. In this instance, it is possible to maximise grip by locking the torque distribution in a 50:50 ratio at speeds up to 25mph. This locked function is activated simply by pressing a button to the left of the steering column, which then illuminates a discreet warning light above the fuel gauge.

Toyota RAV4 all-wheel drive systems: conclusion

Thanks to a minimum ground clearance of 187mm and relatively short overhangs, the fourth-generation RAV4 is capable of riding over heavily rutted tracks and clambering over relatively large obstacles. So although the RAV4 may be categorised as a modern soft-roader, its adoption of Toyota’s technology and four-wheel drive expertise means the RAV4 is anything but ‘soft’.

2014 Toyota RAV4 all-wheel drive badge

83 comments

  1. Hi
    I have a 2014 model rav4 124CV awd and I am French. I found your blog because I search information about a problem on my rav4. Every time I start after a stop I hear a “clonk” noise coming from rear. Sometimes this noise disappear particularly with very hot wheather. Toyota didn’t found anything : they have verify brakes pads but it is not the cause.
    Curiously this noise never appear when the vehicle is moving ; only once time after starting.
    Si I hope to find help with others users.
    Thanks for your help

    1. Hi Andre,
      Unfortunately we have to recommend contacting Toyota France as they will be able to provide the best advice!

    1. Hi Fernando,
      Thanks for getting in touch. When the four−wheel drive lock switch is pushed, the four−wheel drive lock indicator light blinks twice and remains on until the four−wheel drive lock is canceled. To cancel the four−wheel drive lock, push the switch once again and the four−wheel drive lock indicator light will go off. When the vehicle speed exceeds 40 km/h (25 mph), the four−wheel drive lock will be cancelled automatically. Hope this helps!

  2. I have a 2014 Rav4. I drove it From Salem Oregon, to Missoula Montana, and back, in December of 2016. In this trip, I encountered up to 1 foot of snow, lots of ice, heavy rains, and some high winds and drove in elevations close to Sea Level, up to about 4000 feet above sea level. Temperatures for this trip ranged from 10 degrees Fahrenheit to about 45 degrees Fahrenheit (both daytime and nighttime driving). Speed limits in some areas on this trip were 70 MPH, and I drove the speed limit most of the time (slowed down a little during bad weather stretches). My Rav4 performed great for this entire trip. I just left it in Economy mode for the entire trip (I never use the Sport mode), and I did not bother pressing the “wheel lock” or “traction control” buttons (I just left those at the default settings). I had chains in the back of my Rav4 for this trip, but I did not need them. I was especially impressed at how my Rav4 was able to adjust to/from snow conditions, to dry pavement conditions, and put itself into 4-wheel drive automatically, when needed (I don’t really notice it doing so, it just does it behind the scenes). I found the article above very interesting, and informative, as to how the 4-wheel drive system works, on the Rav4. By the way, for the above mentioned trip, never once did I notice any wheel slippage, or any indication of what the Rav4 was automatically doing, at times when it applied more traction to the back wheels (was totally seamless to me, as a driver). Good to know that the tech behind my Rav4 4-wheel drive system was in operation during this trip (that way I could just focus on driving my car, figuring the Rav4 would automatically adjust power to the rear wheels, whenever needed). Also nice that there were never any annoying lights such as “snow light” or “ice detected light” and such (the Rav4 just did what it needed to do, without telling me what it was doing). By the way, I was under time pressure get from point A to point B, in the above mention trip, and often times I was driving fairly fast, in snowy and icy conditions (again, good to know that my Rav4 was setting itself for maximum traction, automatically, for example when I would go over an icy bridge). Also nice is how my Rav4 gets pretty good mileage on the highway (as I recall, it says 29 MPG on the window sticker, and I do believe it gets that, at times where the road is flat, strait, and dry, and the front wheels alone can be used to power the vehicle). I think this great MPG is due to the 6-speed transmission, aerodynamic design, and also my Rav4 has the lower-profile stock tires, with taller rims (I think those wheels help with the mileage a little, and these tires are wider, which I think helped a little in the snow/ice).

    1. Hi there,
      Thank you so much for all your feedback. We’d love to see a picture of your RAV4 on it’s journey. If you want to post a picture to our social channels we’d greatly appreciate it. Many thanks!

      1. Hi Anthony,
        That looks great! We hope you and your RAV4 have many more happy journeys. 🙂

  3. Hi I have a 2015 rav4 limited
    I turned on the 4wd option in many situations never stays on. It goes off in few seconds! !!? Is that a problem! !?

    1. Hi Jawad, thanks for reaching out. We suggest taking your Rav4 into your local Toyota dealer to look at this further for you. Thanks.

    1. Hi Tony,

      Thanks for getting in touch with us.The RAV4 with the V6 engine is not sold in the UK. Therefore, the information we have on this vehicle is very limited.

      However, we believe that the 4WD system used on this vehicle is very similar to the system used in a UK spec RAV4. Therefore, in order to keep the 4 wheels engaged the driver has to press the Four-wheel Drive Lock Switch on the dash. Please bear in mind that the system will automatically disengage the LOCK mode when the vehicle speed exceeds 25 mph. If the LOCK mode is disengaged, the 4WD system will operate in “AUTO” mode where it will automatically distribute drive torque to the front and rear wheels according to the driving conditions in order to achieve smooth acceleration and driving stability.

      You can find more information on our blog here: http://fal.cn/QGNE

      I hope this helps.

      Thanks

      Maria

  4. I got stuck getting out of my driveway. I pressed the lock button and the second the tires spun, it popped out of four wheel. Had to shovel for a long time! Late for an appointment! This sucks! I love my 2014 RAV 4 but thinking about a Subaru that stays in 4 wheel drive!

    1. The moral of your story; don’t spin tires in snow – it makes ICE. The LOCK function will disengage it 25 mph, which you probably easily exceeded while using your “floor-it-to-get-out-faster” technique. In snow (and on ice), “easy does it” is the way to go. A rolling tire has grip. A tire that is spinning wildly, even on dry pavement, has none.

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