Variable Gear Ratio Steering (VGRS)-equipped Lexus LS cars will soon be subject to a recall from Lexus:
Since March of this year, TMC has been looking into this topic after receiving about ten complaints from Japan. No accidents involving this issue have been documented, and there have been no reported instances of this worry in the UK market, either.
By altering the gear ratio, VGRS is a function that makes driving more manageable at low speeds and more stable at high speeds than traditional steering.
When maneuvering the steering wheel to the full lock position at a low speed, the issue occurs. Even though the driving wheels would be straight, a steering wheel off-center condition could result if the driver quickly twists the steering wheel back. The driver may detect the correction when the steering wheel center slowly slides by itself to the center position while driving straight during the correction procedure. This phenomena will be automatically addressed in a few seconds. The steering wheel self-corrects while the driver still has control of the car.
The LS 460, LS 460L, LS 600h, and LS 600hL are included in this recall, which affects roughly 11,500 vehicles globally (3,800 in the USA, 4,500 in Japan, 70 in the UK, and the rest distributed among foreign markets).
In This Article...
What on a Lexus does VGRS stand for?
There are various benefits to having control over a vehicle’s steering ratio. A faster ratio (fewer lock-to-lock turns) can make a car feel more agile. A slower ratio (more spins lock-to-lock) provides a better sensation of stability at high speeds. Although Lexus is not the only manufacturer to use a computer-controlled system to alter ratios, its strategy is quite deceptive. The variable-ratio units with rack teeth cut at various angles are less complex than this sort of active steering since they are unable to adjust the ratio on the fly over the entire range of lock. The more complicated Lexus (and Audi) method essentially involves a gearbox incorporated into the steering column between the steering wheel and the pinion gear. The Variable Gear Ratio Steering (VGRS) system from Lexus uses a wave generator and a flexible gear in contrast to the active steering system from BMW, which uses a planetary gearbox. Lexus asserts that its system is faster and more accurate than others. The LS sedan, the LX SUV, and the brand-new GS F Sport all include VGRS. In order to understand how the device operates and to learn what a wave generator is, we cut into it.
What exactly does VGRS mean?
The automaker claims that the steering wheel may become decentralized when starting the vehicle right after it has been parked with the steering wheel turned because the electronic control unit for the vehicle’s variable gear ratio steering is not likely to have been correctly calibrated at the factory.
Even better handling than the highly praised outgoing Swift, which went on sale for the first time five years ago, is made possible by variable gear ratio steering, bigger track, larger diameter wheels, and lower profile tyres.
Even superior handling than the acclaimed outgoing Swift, which originally went on sale five years ago, is made possible by variable gear ratio steering, bigger track, larger diameter wheels, and lower profile tyres.
It was one of four models, including its two hybrid versions, that Toyota voluntarily recalled in Japan in late May because of issues with the variable gear ratio steering system, which directs the wheels of the vehicle to revolve in tandem with the steering wheel.
According to Toyota spokesman John Hanson, the issue will be fixed by changing the computer processor in the vehicle’s variable gear ratio steering system.
What does the Land Cruiser Vgrs symbol mean?
Since May 2005, Land Cruiser 100 Series Sahara cars have had a Variable Gear Ratio Steering (VGRS) system installed, which has its own set of repair procedures for wheel alignment. Reconnecting the battery terminals and performing other servicing repairs
How does steering with variable ratio function?
The ratio between the theoretical turning radius based on ideal tire behavior and the actual turning radius based on actual tire behavior is known as the steering ratio. Variable-Gear-Ratio Steering refers to a rack and pinion steering system that uses different ratios on the rack.
Electronically Controlled Variable-Gear-Ratio Steering refers to a variable gear system that is electrically powered and controlled by a microprocessor. The distance between the teeth is narrower at the middle of the rack and gets wider as the pinion descends it.
A larger ratio is present in the middle, and when the steering wheel is turned toward lock, a lower ratio is present. As a result, the steering becomes less sensitive when it is in the center, making it more difficult for the driver to oversteer at high speeds. The wheels start to respond more readily to steering input as the steering wheel is turned near lock.
An electronically controlled variable gear ratio steering assembly has the advantage of automatically adjusting to the best steering condition for the current vehicle speed. When driving at highway speeds, the steering of the car becomes less responsive to little wheel movements, whereas when parking or moving slowly, the steering becomes more responsive to small wheel motions.
Electronic steering aids in intelligent steering. An intelligently regulated electric motor is used by the electromechanical power steering to control and assist vehicle steering. The ECU determines the ideal steering assistance based on the steering signal captured by the torque sensor and sends this information to the electric motor, which applies the required force.
Variable gear ratio: what is it?
When using a steering system with a variable gear ratio, a control unit assesses the vehicle’s condition in relation to the road conditions in order to establish the steering angle ratio that should be attained by the steering angle ratio varying unit. The road surface frictional coefficient may be one of these vehicle conditions. In such cases, raising the steering gear ratio will help prevent excessive steering on slick road surfaces. In order to prevent excessive steering when there is minimal margin in the side force available for the steerable wheels, such vehicle situations may also contain a side force utilization ratio of the steerable wheels. In order to increase the steering gear ratio when the vehicle has traveled or drifted sideways more than anticipated, the steering system may include a CCD camera for determining the lateral position of the vehicle relative to the current driving lane and a control unit for predicting the predicted lateral travel of the vehicle, typically from the steering input angle and the vehicle speed. This stops the car from unintentionally drifting out of the driving lane.
My AFS light is on, why?
When it is safe to do so, pull over to the side of the road and turn off the engine if the AFS indication illuminates and begins blinking while you are driving. When driving with the ignition switch in the ON (II) position, if the AFS indicator blinks continuously or blinks once more, the AFS is malfunctioning (see page ).
What steering ratio is ideal?
The typical steering ratio for an automobile is between 24:1 for manual steering and 14:1 for power steering assistance. The easier it is to turn the wheel and steer the car, the higher the steering ratio. More effort is required at the steering wheel as the ratio decreases.
What steering ratio would be ideal?
The steering ratio is the proportion of wheel turn to handlebar or handlebar turn (measured in degrees) (in degrees).
[1]
The steering ratio measures how many degrees the steering wheel is turned in relation to how many degrees the wheels turn as a result. Because the steering wheel is permanently attached to the front wheel, the steering ratio on motorcycles, delta tricycles, and bicycles is always 1:1. When the steering ratio is x:y, the wheels turn by y degrees for every x degrees the steering wheel is turned (s). The ratio in the majority of passenger cars ranges from 12:1 to 20:1. For instance, the ratio is 360:75 = 4.8:1 5:1 if a 360-degree rotation of the steering wheel causes the inner and outer wheels to turn 30 and 45 degrees, respectively.
In order to turn the wheels, the steering wheel must be turned more, yet it will be simpler to turn with a greater steering ratio. Although it will be more difficult to spin the steering wheel, a lower steering ratio means that turning the wheels requires turning them less. The steering wheel will be simpler to turn because larger, heavier cars frequently have higher steering ratios. It would be quite challenging to turn the steering wheel in a truck with a low steering ratio. The wheels are simpler to turn in regular and lighter cars, requiring a lower steering ratio. Due to the need for the vehicle to react to steering input much more quickly than in regular automobiles, the ratio in race cars is often relatively low. As a result, turning the steering wheel is more difficult.
How can I tell whether my automobile has power steering with variable assist?
Seek Out The Code 1SC on the Lid of Your Trunk Another option is to peek inside the trunk lid of your car. The build tag must be located. Find 1SC in the constructed tag. Your variable-assist steering will be ensured by these three letters.
What benefits can variable help power steering, variable ratio steering, and steering offer?
A growing number of automobiles use power steering with variable-assist, variable-rate, or variable-effort. The best of both worlds may be had with variable help: low-speed parking maneuverability at the touch of a finger, and less aid at higher speeds for more stability and road feel.
Less effort and assistance are required to guide the wheels as a vehicle speeds up. Contrarily, variable-rate steering provides more assistance when it is most needed at low speeds and less assistance when it is least needed at higher speeds.
Variable steering: What is it?
With a technology called variable assist power steering, the amount of assistance varies with the speed of the car. For instance, a Ford variable-assist power steering vehicle steers with less assistance and effort as the speed rises. Power steering with variable assistance provides more assistance at low speeds and less assistance at higher speeds. Drivers may control their vehicles at low speeds with just their fingertips thanks to the variable-assist power steering.
The pressure applied to the steering gear is primarily adjusted to achieve this. With this method, the control unit receives signals from the steering wheel rotation and wheel speed sensors on the car and adjusts the pressure as necessary. By lowering the amount of fluid flowing into the steering gear system, the control unit achieves this. This improves the car’s stability and keeps it from careening or spinning out of control.
The steering support offered can be changed by the variable-assist power steering system by adjusting the steering valve inlet pressure and vehicle speed. A system controller is tasked with receiving speed and pressure information from the sensors. The variable-assist steering actuator, which transfers fluid from the pump to the steering valve, receives a control signal from this controller. The steering valve pressure, which regulates the rack piston and modifies the angle at which the car’s front wheels turn to steer, is impacted by this movement.
A crucial part of variable-assist systems is the EVO (Electronic Variable Orifice) valve. The EVO entirely opens when the vehicle is moving at less than 40 mph to allow enough hydraulic fluid to flow from the power steering pump to the steering mechanism. resulting in maximum power assistance. When that speed is reached, a control module instructs the EVO to limit the flow of hydraulic fluid. As a result, the assist is minimized, which enhances road stability and improves control at such high speeds. The EVO valve, control module, and vehicle speed sensors must be functional for a variable-assist power steering system to operate. In the event that one of these parts fails, the vehicle may lose power assistance or experience a loss of controlled assist.
Because the steering angle sensor is typically to blame for system problems, variable assist power steering systems are dependable. The contacts may become worn out, which could lead to the control unit receiving the incorrect signals.