Your car brakes are an essential component of a safe traveling experience.
However, with faulty speed sensors, it’s difficult to have control of your brakes. This is a mechanical issue that can occur anywhere along your journey. If not attended to, it can lead to other mechanical problems like ruining your best brake pads.
This article will equip you with skills on how to fix your car’s speed sensors hassle-free, even in absentia of your professional mechanic.
What is a Speed Sensor?
A car speed sensor is a component mounted at the transmission case or inside the Anti-lock Brake System. It is also referred to as a wheel speed sensor or Anti-lock brake system Speed sensor.
What are the Functions of a Car Speed Sensor?
It monitors the rotational speed of each tire and relays the information to the Anti-lock Brake System (ABS) control module and Engine Control Unit (ECU) to help them work for the good of other car systems such as drive axles, transmission, and brakes.
In normal circumstances, a combination of a tire and a wheel will operate smoothly on the same axle, rotating at the same speed.
When one wheel is rotating faster or slower than the others due to less traction, it is the work of the car speed sensor to inform the system to increase or decrease pressure. The ABS module comes in and helps you to stop your car safely.
An Anti-lock Brake System(ABS) is a safety technique that controls your car from sliding or skidding when you apply the brakes.
When you apply brakes, the ABS reads information from the speed sensor and sends the ideal pressure from each wheel thus preventing the wheels from locking.
Also, in modern cars, Anti-lock Brake system (ABS) speed sensors work together with electronic Traction Control Systems and Stability Control Systems to maintain the stability of the car.
In modern cars, speed sensors are being used to determine ride height.
‘’The difference between a car with and without an active Anti-lock Brake System is potentially a matter of life and death. Your brakes will still be functional, but the chances of locking up on a slippery road are very low without an Anti-lock brake system and very high with it.’’
What causes a Faulty Wheel Speed Sensor?
Mostly, Wheel speed sensors are fairly durable. The main reason for faulty speed sensors is wear and tear. This is because any time your car is in motion the speed sensors are in use. Hence, it’s unavoidable.
Another reason is too much exposure to wet weather conditions. When your car is moving on a slippery road, your speed sensors are likely to be more active than in normal circumstances thus, shortening its lifespan.
Also, Faulty speed sensors may be as a result of dust, dirt from excessive grease, or even debris and other objects. They can either be dirty or broken. Consider cleaning them first using a car spray.
‘’Ensure you inspect your sensors and clean them in the intervals outlined in your manufacturer’s guide.’’
What are the Symptoms of a Defective Car Speed Sensor?
If you are already experiencing the following signs with your car, It may be an indication of a faulty speed sensor:
- Inconsistent Speedometer Readings – It occurs when the pointer at the speedometer fails to maintain a certain speed even when your car is moving at a constant speed.
- Illuminating Light on your Dashboard from the Anti-lock Brake System light or traction control light.
- Loss in traction when driving under slippery road conditions.
- Transmission difficulties when changing gear and sometimes even revving higher before shifting.
- Cruise control stops performing properly.
- Fuel efficiency drops.
How to Fix Your Car Speed Sensor?
It is important to note that, a defective speed sensor may relay symptoms similar to those of a failing transmission. Therefore, it is important to perform a diagnostic on your car. It will easily reveal which sensor is faulty. Then follow the following procedure to fix your speed sensor.
Ensure you have the right tools and safety equipment for the job:
- Scan tool
- Socket wrench
- Torque wrench
- An Allen key flashlight
- A flat head screwdriver
- Jack stands
Ensure that you have your best ceramic brake pads and that the new wheel speed sensor is compatible with your car model and make. It is advisable to change the entire brake system since the brake pads are prone to wear and tear and you will still replace them sooner or later.
Look for a leveled ground, park your car and put off the engine. Scan the ABS for codes, inspect the entire brake system and the reluctor wheel
Lift your car using the jack and place the stands beneath to keep your car in position. Ensure that the stands are well grounded before lowering your car onto them.
Get set to pull the lug nuts loose using ½ inch drive breaker bar and a lug nut socket. Then remove the wheel.
Remove the brake pads and rotors to get a clear view of the bolts holding the sensors on the hub. Remove the old speed sensor and any clip supporting the sensor wiring on the car’s body.
Using step 3 instructions in reverse order, install the new speed sensor and your best ceramic brake pads. Reinstall the rotor and the brake caliper bracket together with the brake pads.
Reinstall the wheel(s) back to the hub and use the lug nut sockets to tighten the lug nuts. Lift the car using the jack and remove the stands then lower your car.
Rotate the wheels back using the Torque wrench to twist the lug nuts to their proper specification.
Take your car for a test drive and ensure that all the symptoms you observed before fixing the speed sensor can no longer appear.
How much does it Cost to Fix a Speed Sensor?
The cost of fixing a speed sensor is determined by the model and make of your car. It is also determined by the type of speed sensor your car is using. However, it is fairly cheap to replace a speed sensor. Normally, the cost ranges between $225 and $380.
A defective speed sensor should be replaced as soon as possible to avoid further damage to your car. When you fail to take quick action on a defective speed sensor, you only expose yourself to more mechanical expenses. With knowledge and skills on how to fix your car’s speed sensors, you can have your Anti-lock Brake system operating to optimal effectiveness.