You may have noticed a red light on your dashboard when driving a Toyota car that reads “Auto LSD.” It serves as a signal for a helpful system in your car. So, what does this “Auto LSD” do on a Toyota RAV4, Tundra, Tacoma, and other models?
Auto LSD stands for Automatic Limited-Slip Differential. It refers to the Toyota traction control system, which automatically reduces engine power and applies brakes when it notices that one of the rear wheels of your car is slipping and starting to spin.
The technology only works when the vehicle is in two-wheel drive. Four-wheel drive does not activate it. Auto LSD improves vehicle control on most Toyota models, including Tundra, Tacoma, and RAV4.
Read on to learn more about the benefits and the characteristics of Auto LSD on different Toyota models.
What Is an Automatic Limited-slip Differential (Auto LSD)?
Auto LSD is a function found in Toyota vehicles with open rear differentials. When Auto LSD is activated, it simulates a limited-slip differential.
While Auto LSD is only meant to be used in extreme circumstances, a standard limited-slip differential is a mechanical component that you can’t turn on and off.
Auto LSD will be activated even when a mechanical limited-slip differential is available. It will continuously distribute power to the rear wheel that requires it the most.
This system will engage the brake to lock the spinning wheel effectively. It also redistributes power to the wheel with the best traction.
This is exactly what a traditional limited-slip differential would do when one wheel is slipping. Auto LSD effectively combines the advantages of a limited-slip differential and a locking rear differential on a vehicle with an open rear differential.
Auto LSD on Different Toyota Models
1. Toyota Tacoma and Tundra
Automatically Activated in Rear-wheel Drive
When your Toyota Tacoma or Tundra is in rear-wheel drive, Auto LSD is automatically activated. However, you can always override this setting by pressing the Auto LSD button. This feature is always in the background, even when the Auto LSD light is not flashing on your dashboard.
Limits Engine Power to Less Than 1,000 RPM
Auto LSD limits engine power to less than 1,000 RPM on a Toyota Tacoma if it notices that one of the rear wheels is beginning to slide. It also applies brakes to the slipping wheel and sends more drive to the wheel with the best traction.
Transfers Power to the Wheel with Traction and Brake the Slipping Wheel
The system will still transfer power to the wheel with traction and brake the slipping wheel if you use the Auto LSD button, but there will no longer be any limiting engine output here.
Shuts Off When You Have an Activated Four-wheel Drive
When the Auto LSD light is on, pressing the gas pedal will cause the engine’s RPM to rise to the same level as usual.
You do not have to remember to toggle Auto LSD on and off when you go between rear-drive and four-wheel-drive modes is part of what makes it “automatic.”
The Auto LSD system entirely shuts off once the four-wheel drive is active. Plus, you can’t turn it back on unless you switch your vehicle back to rear-wheel drive.
2. Toyota 4Runner
Useful When Driving in Muddy Sludge
When you are driving and wish to keep going forward in the sloppy, muddy sludge with a firmer grip on your vehicle, the Toyota 4Runner Auto LSD will come in useful.
How to Activate
The Auto LSD option works on the rear differential in two-wheel drive mode. Here is how to activate it on a Toyota 4Runner:
- Press the VSC off button once to activate Auto LSD.
- A light that reads Auto LSD and a car icon with two wavy lines will be visible. This shows that the auto LSD is active, and the traction control has been disengaged.
- The indicator will flash to show Auto LSD is managing the spinning rear wheels.
- This feature will be excellent when you need extra traction but do not want to switch to a four-wheel drive.
- Turn off the Auto LSD by pressing and holding the same VSC off button for three seconds.
Differential Ensures That You Can Drive Both Wheels on the Axle
A differential lock will account for the speed differential when turning. One wheel may spin on a soiled surface while the other does not if the road’s surface is different.
The differential ensures that you can drive both wheels on the axle when the locking effect is 100%, especially when the road’s surface is muddy.
The cool thing about a sporty car like a 4Runner is that the power will transmit to the opposite wheel when one is spinning.
3. Toyota RAV4
Do Not Turn This Feature on When the Wheels Are Spinning
With a Toyota RAV4, you should only use the Auto LSD system under tough and harsh weather conditions, such as deep snow or driving off the road. Moreover, do not turn this feature on when the car is moving or spinning wheels.
Auto LSD may also require increased steering effort as soon as it is active on a RAV4. When cornering, for instance, you will need to be extra careful to maintain full control. The Auto LSD icon will start flashing as soon as your car slips.
How to Activate Auto LSD on a RAV4
You can activate it by pressing your car’s “VSC Off” switch. This button features the word “Off” with two wavy lines behind the wheels.
VSC Off and Auto LSD indicators will flash when they are on, indicating that the system is active. To switch it off, press the “VSC Off” button and hold it for about 3 seconds.
Auto LSD vs. Traction Control
When driving under typical conditions, traction control helps to maximize control over your RAV4. When a wheel slips, it applies brakes to that wheel and limits engine power.
Auto LSD, on the other hand, distributes power to the wheel with the most traction instead of lowering engine power to propel the wheel forward, as with traction control.
Moreover, activating the Auto LSD will automatically disable traction control.
Why Does Auto LSD Automatically Turn Off on a RAV4?
The Auto LSD system will turn off automatically if the brakes overheat while in use. However, it will be automatically restored after a short period.
Moreover, the system will turn off automatically when the engine is turned off and stay off when you restart the engine.
What Is Auto LSD Used For?
Provides the Rear Wheels Extra Grip
Auto LSD is a helpful option for giving the rear wheels of your Toyota vehicle some extra grip in challenging situations.
Although mud, sand, ice, or snow provide more traction to the rear wheels of your Toyota vehicle, that is not the case with Auto LSD.
These days, most SUVs and trucks have all-wheel-drive and four-wheel-drive systems and locking differentials to handle rugged terrain and surfaces, while performance vehicles have limited-slip differentials.
Limits the Torque Sent to the Spinning Wheel
This is so that an Auto LSD can limit the torque sent to the spinning wheel while simultaneously maximizing the torque sent to the wheel with the most traction. This allows each rear wheel to turn at different speeds without being completely locked to each other.
Increases Traction When Negotiating Bends at High Speeds
In performance vehicles, Auto LSD increases traction when negotiating bends at high speeds by increasing torque supplied to the rear wheel with the most grip and decreasing torque delivered to the wheel with the least grip.
Functions Much like an Open Differential up Until Slippage Happens
The Auto LSD will function much like an open differential up until slippage happens, allowing the drive wheels to revolve at various rates. It can detect when a certain amount of slip occurs mechanically or electronically as a wheel torque or speed difference.
Then, it reduces it by linking the wheels using a clutch, viscous coupling, or pressure between the gears.
Again, what does Auto LSD mean? Toyota’s Automatic Limited-Slip Differential or Auto LSD is a traction control system that controls the engine output and braking when your rear wheels are losing grip or spinning.
Benefits of an Auto LSD on a Toyota Vehicle
1. Off-Road Traction
Auto LSD provides improved off-road traction compared to an open differential. This results from the limited-slip differential transferring power to the traction-equipped wheels.
2. Paved Surfaces
It allows your vehicle to perform just as well off-road as they do on paved surfaces. The traction is almost flawless, so that the performance will be superb.
3. Less Tire Wear
This helps minimize excessive tire wear because the Auto LSD can transfer power from a wheel that is losing traction to another. Otherwise, the tire with poor traction would spin continuously and wear out more quickly.
4. Less Wear on the Axle Shaft
The axle shafts will not be pressured during turns because they can rotate at different speeds. They will not wear out as quickly because of this.
Disadvantages of Using Auto LSD on a Toyota Vehicle
1. Insufficient Power to the Wheels
The Auto LSD will not be able to send all the power to a wheel with traction. Even though it has removed a lot of power from the wheel that lacks traction, it will always need to send a little power to it. It cannot transmit all of its ability to a single wheel.
2. Difficult to Manage Sometimes
When driving on rocky, muddy, or sand-covered roads, it will not always be possible to forecast what the traction will do. Although the Auto LSD will transmit some power to the wheels that are losing traction, this power will not be available consistently.
The differential will transfer more power to those wheels as soon as other wheels lose traction. In other words, this can sometimes pull your vehicle in one direction only.
3. Not All Are the Same
Auto LSD will work slightly differently depending on what Toyota model you have. So, no type of differential would function the same way among all Toyota models.
What Is Auto LSD?
Auto LSD stands for Automatic Limited-Slip Differential, and it should only be used in the event of slippage in extremely difficult conditions, such as off-roading. Otherwise, you would not want to use it when driving usually.
When the Auto LSD dashboard warning light is flashing, the system is active and working to keep your car under control to prevent any slippage.
Does the Auto LSD Automatically Turn Off?
Yes. The Auto LSD system will turn off automatically if the brakes overheat while in use. However, it will be automatically restored after a short period. Plus, the system will turn off automatically when the engine is turned off and stay off after you start.
When one of the rear wheels starts to spin, the Auto LSD system uses the traction control to manage engine output and braking, increasing traction on the wheel that is not spinning. This is why you should turn it on only when one of the rear wheels spins on a rough surface.
When the rear wheels start to spin, the red light will flash to show that the Auto LSD system has stopped them from spinning.
Does My Car Need an Auto LSD?
If your car already has four-wheel drive, especially with access to both high and low range, Auto LSD is unnecessary for you. However, it is a different story if you travel off-road often and put your vehicle through difficult conditions.
Rear-wheel drive performance cars require an Auto LSD, while all-wheel drive is best for performance cars or SUVs in states where snow and ice can be a problem in the winter.
When Can I Use Auto LSD on My Toyota Vehicle?
You should use the Auto LSD only when driving in challenging conditions, such as off-road or deep snow. If you are somebody who drives around the city, Auto LSD might not be of great help.
Moreover, you will need more effort into steering when using the Auto LSD. Plus, you should drive more carefully around corners to maintain full control of your Toyota vehicle.
Once you lose control over the wheels, the Auto LSD will flash a red light on your dashboard. This warning light says that the system is active and trying to control the slippage.
What Is a Limited-slip Differential?
It is that part of a car that divides torque from transmission between the wheels. All cars have a differential, but only some have a “limited-slip” differential. An LSD determines whether a car can maintain traction even in slippery situations like mud, rain, snow, or ice.
A differential enables the wheels of a car to move at various speeds, which plays an important role while turning your vehicle. This is why the outside wheels of your car have to move a little farther than the inside wheels as you make a turn.
If you try this without a differential, your car may buck or skitter across the pavement. However, it allows the outside drive wheel(s) to revolve more quickly than the inside one(s) to maintain momentum. Auto LSD enhances it by limiting your chances of slippage on the road.
What Does the Limited-slip Differential Exactly Do?
It uses engine power more effectively to boost your car’s speed. This will result in a smoother and more pleasant ride. Even on common roads, it can help maintain near-perfect traction to provide a safer and more comfortable ride.
Is It a Problem If My Toyota Car Does Not Have an LSD?
No, not always. The traction-control system in many modern cars can effectively prevent slippage by applying the brakes to stop a spinning wheel and allowing the other wheel on the same axle to use its grip to propel the car. However, an LSD is a more effective way to convert the torque of an engine.
Does an LSD Make Noise When Turning?
An LSD may become noisy and vibrate when regular differential fluid is added. Two wheels can rotate at different speeds during turns by overcoming clutch strain. Others have friction plates, while some others have cones.
Conclusion – Auto LSD on a Toyota Tundra, Tacoma, RAV4, and 4Runner
When the Toyota traction control system detects that the rear wheels of your car are slipping and starting to spin, it automatically cuts engine power and applies the brakes. This is what “Auto LSD” is all about. Toyota Tundra, RAV4, 4Runner, and Tacoma have this Auto LSD feature.
This technology works well when the car is in two-wheel drive. Auto LSD simulates a limited-slip differential, and once it is active, it allows the brakes to effectively lock the spinning wheel and shift power to the wheel with the best traction.
Above all, the best thing about Auto LSD is that it helps a great deal with off-road traction while minimizing pressure on your car tires and axle shaft.