What are the types of vehicle speed sensors?

[StFaith]

Vehicle speed sensors are categorized into magnetic speed sensors, Hall-effect speed sensors, and optical speed sensors. The vehicle speed sensor is a device used to detect the speed of electronically controlled vehicles. The control computer utilizes this input signal to regulate engine idle speed, torque converter lock-up in automatic transmissions, automatic transmission shifting, activation/deactivation of engine cooling fans, cruise control functions, and other operations. Typically installed in the drive axle housing or transmission case, the sensor's signal wires are encased in shielded conduits to mitigate electromagnetic and radio frequency interference from high-voltage ignition systems and electronic equipment. This ensures uninterrupted electronic communication and prevents degraded driving performance.

[OAmara]

In my years of driving experience, there are quite a few types of vehicle speed sensors, with the common ones being wheel speed sensors and output shaft sensors. Wheel speed sensors are installed on the wheels, used for the ABS system to measure the rotation speed of each wheel. They are generally magnetoelectric or Hall-effect types. For example, Hall sensors are triggered by magnetic wheels, offering fast response and fewer errors. Output shaft sensors are located near the transmission and control shift smoothness, often using similar designs. The older magnetoelectric types rely on changes in the magnetic field of a coil but are prone to interference from iron debris. Photoelectric types use light sensing for detection but are sensitive to dust and fog, making them rare in vehicles. Additionally, GPS speed sensors in newer cars assist in displaying vehicle speed, but the core still relies on mechanical sensors. Sensor failures can lead to unstable braking or jerky gear shifts, so it's best to regularly clean wheel speed sensors to prevent the ABS light from coming on.

[SanPhoebe]

When repairing cars, I commonly encounter several types of vehicle speed sensors: magnetic induction, Hall effect, and optical. The magnetic induction type is the most basic, using a coil and magnet to detect rotational speed—it's inexpensive but prone to noise. The Hall effect type is the mainstream choice, featuring an internal chip to measure the rotation of a magnetic wheel, offering precision and durability, often used in ABS systems. Optical sensors determine speed via a light-emitting diode and receiver but are sensitive to dirt and require a sealed environment, commonly installed on wheel axles. Output shaft sensors in the drivetrain function similarly to Hall effect or magnetic induction types, providing speed data to the transmission and dashboard. Modern vehicles may also use GPS or inertial sensors to supplement data. These sensors have varying lifespans: magnetic induction coils are prone to aging, while Hall effect sensors are more reliable. Choosing the right type can reduce the frequency of failures.

[CooperDella]

Vehicle speed sensors mainly include wheel speed sensors, output shaft sensors, and a few photoelectric types. Wheel speed sensors are installed at the wheels, and ABS relies on them for speed measurement to prevent lock-up. The output shaft sensor is located on the transmission output shaft, aiding in smooth gear shifting. Their working principles are divided into magnetoelectric type (generating voltage through magnetic field changes) and Hall effect (electron sensing), with the latter being more precise and widely used in modern vehicles. Photoelectric types are rare due to susceptibility to contamination. When a sensor fails, the speedometer may become inaccurate or warning lights may illuminate, requiring prompt inspection and maintenance.

[ArcherLynn]

There are various types of vehicle speed sensors nowadays. For instance, magnetic induction sensors are simple on older vehicles but vulnerable to vibration; Hall effect sensors are efficient and durable, commonly used in ABS and transmission systems; photoelectric sensors are rare in automotive applications. During vehicle maintenance, I found that the output shaft sensor is crucial for controlling gearshift logic, while wheel speed sensors are mostly Hall-type and easy to clean. GPS assistance provides speed data in new vehicles, but mechanical sensors remain the backbone. Regular inspection of connections to prevent corrosion can extend their lifespan and prevent accidents.