Wheel speed sensor information about the need for replacement

Wheel speed sensors are often referred to as Anti-lock Braking System  sensors, as they were first used in vehicles equipped with this system.

Working Principle of the Sensors

Impulse sensors are firmly fixed on the hub of every wheel or on the drive shaft. The gap between the stationary sensor and the rotating part is up to 5/64 inches, as designed by the vehicle's construction. The rotation of the wheel leads to a change in the magnetic flux, and signals from the sensors are sent to the Anti-lock Braking System unit, thereby measuring the speed of each wheel.

Anti-lock Braking System sensors are divided into two groups:

  • Passive sensors are less accurate, but sufficient for the normal operation of the anti-lock braking system. The downsides include the inability to determine wheel rotation speed when the vehicle is moving at speeds less than 3-5mph. The advantages include the simplicity of the device and its durability.
  • Active sensors are further divided into Hall sensors and magnetoresistive sensors. The latter detect both the speed and direction of the wheel's rotation. The main advantages of these sensors are their high measurement accuracy and reliability.

Reasons and Consequences of Sensor Malfunction

Most often, sensors fail due to oxidation of contacts, wire breaks connecting the sensors to the electronic control unit, and these breaks primarily occur near the connectors. The sensor begins to malfunction intermittently when the integrity of the cogged wheel is compromised.

Signs of a malfunction that require you to contact a repair shop:

  • The Anti-lock Braking System warning light comes on;
  • Delayed response from the brake pedal;
  • Need to apply excessive force to the brake pedal;
  • Brakes locking up.

 Go out to a flat road and check the brakes' behavior. If they act erratically, engage at inappropriate times, or the braking force doesn't match the pedal pressure, there might be a defect in one of the ABS components. However, if the ABS warning light is constantly on, the driver should inspect the system's sensors. It's best to visit a certified auto service center for diagnostics and repairs. Reading ABS errors with a standard car scanner typically doesn't yield results. Specialized diagnostic equipment and tools available at auto service centers are required. The sensors' condition can be determined without removing them from the car. To extend the sensor's life, it's essential to have regular professional maintenance, and consult specialists at the first signs of malfunction. The sensor itself is conditionally repairable. We don't recommend rewinding a new coil or restoring the casing and gear/magnetic ring integrity. Instead, replace it with a new sensor.

Wheel speed sensor replacement involves the following steps:

  • The sensor mounting area is cleaned,
  • The wheel speed sensor is replaced. It's also essential to ensure the sensor's cable is correctly routed and secured. Adherence to the vehicle manufacturer's torque specifications is crucial.
  • The fault memory is read and saved faults are cleared. During vehicle diagnostics, the control unit might identify additional faults. They should be cleared before a test drive.
  • To check the wheel speed signal after sensor replacement, a test drive is performed with a connected diagnostic device, and parameters are assessed.

After the test drive, fault memory is read again. As systems in the car are interconnected, a fault in the ABS might also be stored in other control units. It's advisable to query all control units and clear stored errors. 
The wheel speed sensor is a delicate component.

"Wheel speed sensor replacement" fixes "Faulty wheel speed sensor"

The AutoTechIQ ranking for Safety, Cost Avoidance, and Environmental Impact is

env level
env level
Cost Avoidancei
env level
env level
Environmental Impacti
env level
env level
Four common causes for a “tire pressure” warning light on the vehicle and their related parts.
This fix will help eliminating

Tire Pressure Light

The tire pressure light warns about a tire-kinda-empty(at least 25% below proper air), a flat tire, or broken sensors. If it’s the sensors, the tires should look normal. Alternatively, the tires might have overheated and want to cool off.

Stay alert if your car's dashboard begins to pop the "tire pressure" warning light. You might be driving under flat tires, causing progressive damage and requiring hefty repairs in the future; it'll also feature considerable safety risks. Alternatively, it can be electrical issues with the car's computer.

Either way, driving with a low tire pressure light on is pretty risky. So, measure tire pressure every once in a week to ensure you're up to safety standards. Extra tip: bad tire inflation can lightly cause poor fuel efficiency.

Are you having trouble with a tire pressure warning light on your car's dashboard? This warning light indicates issues like faulty wheel speed sensors, broken instrument clusters, temperature changes, old tire pressure sensors, etc. Typically, the symptoms are flat tire, handling difficulties, intermittent dashboard warnings, and much more. In extreme cases, not fixing this can result in a blown-up tire mid-traffic.

Learn More about the Symptom
Four common causes for an “ABS/TCS” warning light on the vehicle and their related parts.
This fix will help eliminating

ABS/Traction Control Light

The ABS and traction control lights are likely on due to driving on slippery terrain, indicating a "mode" the car activated. However, damaged brake and steering system sensors could send incorrect signals, causing the light to stay on continuously. Another possibility is problems with traction or brakes, such as low brake fluid.

Don't ignore those flashing ABS and traction control warning lights on your car's dashboard. They indicate that something is wrong with your vehicle's braking system, requiring immediate attention. The sooner you take action, the better, as the damage could become more severe, leading to costly repairs.

Keep an eye out for any unusual behavior in your car. Read our informative articles to gain the knowledge you need to communicate productively with your mechanic. Together, you can advocate for your vehicle to run at its best.

Learn More about the Symptom

Other Vehicle Symptoms

Below are just a few examples of typical Symptoms and Fixes your car might be experiencing

Is Wheel speed sensor replacement
Your Issue?