WSS-1050 PAT Wheel Speed Sensor

Wheel speed sensors, originally introduced for Anti-Lock Braking Systems (ABS), are now integral to numerous modern vehicle systems. With a focus on safety and customer demand, these sensors have become essential for the operation of intelligent safety systems and other vital vehicle functions.

• Supports multiple control units via advanced data transmission systems like the Controller Area Network (CAN)
• Crucial for driving safety, influencing systems such as ABS, TCS (Traction Control System), ESC (Electronic Stability Control), ADAS (Advanced Driver Assist System), and ACC (Adaptive Cruise Control)
• Assists in engine management, transmission control, and navigation systems
• Significantly impacts vehicle dynamics, driving comfort, safety, emissions, and fuel consumption

Types of Wheel Speed Sensors

Wheel speed sensors come in two types: passive (inductive) and active.

Passive/Inductive Wheel Speed Sensors

• Inductive analogue types that do not require an external power supply
• Consist of a wire coil wound around a soft iron core, connected to a permanent magnet
• Detects the rotation of the wheel hub or drive shaft
• Movement from tooth to tooth on the trigger wheel alters the sensor's magnetic field, inducing an alternating voltage proportional to wheel speed
• Can become inaccurate at low speeds and are sensitive to positioning and damage during maintenance

Active Wheel Speed Sensors

• Digital hall sensor types with integrated electronics, requiring a power supply from the ABS module
• Two types: magneto-resistive and hall sensors
• Generate a digital signal and may have 2 or 3 terminals
• Triggered by opposing magnets around a multipole ring (encoder) or a toothed ring
• Encoders can be located inside the wheel bearing, on the wheel bearing, or on the wheel carrier

Advantages of Active Sensors:

• Accurate wheel speed detection from stationary, crucial for traction control and hill descent control
• Smaller and lighter design
• Insensitive to vibration and temperature fluctuations
• Less sensitivity to changes in air gap
• Reduced electromagnetic interference
• Ability to detect forward and reverse movement

Symptoms of a Faulty Wheel Speed Sensor:

• Multiple warning lights displayed on the dashboard
• Wheels locking during braking
• Pulsation of the brake pedal
• Erratic or no speedometer operation
• Other seemingly unrelated system failures

Troubleshooting and Diagnostics:

When diagnosing a faulty wheel speed sensor, it is crucial to determine if it is inductive or active. Active sensors, common since the late 90s, offer superior accuracy at low speeds and can indicate reverse rotation. If unsure about the sensor type, refer to the vehicle manufacturer’s specifications and procedures.

For effective diagnosis, follow these steps:

• Use a suitable diagnostic tool to read fault codes
• Inspect the wiring for damage or breaks
• Inspect the mechanical assemblies for issues
• Check the output signal using a scope or suitable diagnostic tool
• Check the supply voltage for active sensors
• Check the sensor resistance for inductive sensors

12 Months Warranty

* For correct fitment ensure the vehicle is listed in the compatibility list AND read any notes associated with the product. If there are no vehicle details listed, please send a message.