What Is A Wheel Speed Sensor And Why Is It Important?

Your Toyota has a wheel speed sensor at each wheel. A wheel speed sensor is an important part that provides necessary information about the vehicle's speed to the ECU in order to help other systems, such as the anti-lock braking and traction control systems, function properly. The ECU also feeds the speed data to the odometer and speedometer.

Wheel speed sensors have a couple of other names:

  • Speed sensors
  • Vehicle speed sensors
  • ABS sensors

If you're looking for some information about what a wheel speed sensor is and why it's important, you came to the right place. In this post, we'll discuss what a wheel speed sensor is, how it works, and why it's important. We also have a buyer's guide that covers other areas regarding wheel speed sensors.

Where Is The Wheel Speed Sensor Located?

toyota wheel sped sensor

Image Credit: Nic Wang

The wheel speed sensor is located at the wheel, but where, exactly? On most vehicles, you'll find the wheel speed sensor mounted in the stationary portion of the hub assembly. The wheel speed sensor is always mounted very close to the reluctor ring. The reluctor ring is a mult-toothed timing ring that is mounted in the rotating portion of the hub assembly.

If you're not sure where your wheel speed sensor is, consider taking a look at the service manual for your Toyota.

What Does A Wheel Speed Sensor Look Like?

Toyota oem wheel speed sensor

A typical wheel speed sensor is a small tube-shaped module. These small modules are robust and include both the sensor itself and the mounts. They're usually made out of metal, which makes them very sturdy.

Unfortunately, there's no standard look or shape for wheel speed sensors. They can be shaped like cylinders, tubes, or rectangles. The one thing that stays consistent is their size. They're all very small (about 2-3 inches tall). Each wheel speed sensor comes with built-in wiring that connects to the ECU.

Why Is It Important For Your Car To Have Wheel Speed Sensors?

A wheel speed sensor tells the ECU how fast each wheel is turning at a given moment. Your Toyota's ECU uses this information to determine the tire's rotational speed direction.

Wheel speed sensors are a modern solution. With a wheel speed sensor at each wheel, the ECU can monitor the speed of each wheel separately. This helps the ECU provide accurate information to other systems within the vehicle. Such systems include the vehicle stability control and anti-lock braking systems.

In the vehicle stability control system, the wheel speed sensors inform the ECU when a wheel is spinning at a different speed from the other wheels. This information will allow the VSC to stabilize the wheels and reduce power to keep the vehicle in control.

In the anti-lock braking system, the wheel speed sensors inform the ECU which wheels are moving at a different speed from the other wheels. They also inform the ECU if any of the wheels are locking up while braking.

How Does A Wheel Speed Sensor Work?

Toyota speed sensor

The wheel speed sensor must remain stationary as it detects rotation of the tire. It's mounted right next to the reluctor ring, and it's pointed at the ring's toothed edges.

As the reluctor ring spins, its teeth pass by the wheel speed sensor. The sensor uses magnets or coils of wire to detect this movement. It tracks the speed of the reluctor ring by sensing the pattern of the teeth as they pass by the sensor. The magnetic field or wire coils detect the gap between the teeth on the ring. As the wheel spins, the teeth on the ring disturb the magnetic field or wire coils. The sensor tracks how quickly and often the magnetic field or wire coils are disturbed.

Once the ECU detects rotation of the tire via the sensor, it can determine how fast each wheel is rotating. It then sends this information to other systems in your Toyota.

How Long Does A Wheel Speed Sensor Last?

Wheel speed sensors usually last for the life of the vehicle. The longevity of your wheel speed sensors depends on several factors, including whether you live in an area with corrosive road salt.

It's rare for a wheel speed sensor to fail on its own. Wheel speed sensors usually fail as a result of an external issue, such as physical damage or corrosion.

If you need a replacement wheel speed sensor, we may have what you need. Look up your Toyota model in our catalog of OEM Toyota wheel speed sensors. You'll likely find an OEM wheel speed sensor made for your Toyota model. The best part? You'll get it at wholesale pricing! If you have trouble finding the right part number for your particular Toyota model, we'll be happy to help. All you need to do is contact us.