Symptoms of a Faulty Speed Sensor in Your Vehicle

2 common types of vehicle speed sensor, some type is installed on rear transmission or transaxle, and another type is installed on the knuckle arm on the 4 wheels. Please note this, between vehicle speed and engine speed are different. The engine speed taking data from crankshaft position sensor that give the information of engine spin. And vehicle speed taking data from speed sensor which installed on wheels or on the transmsission that send information of wheels spin. Therefore, any fault on the speed sensor or any symptoms showing how defective it has become can lead to a wide range of abnormal problems in your vehicle if you fail to pay attention to it in time.

Common Symptoms of a Faulty Speed Sensor

  • The transmission will not smoothly change gears

One of the common speed sensor symptoms of your car is that the transmission will not smoothly change gears of your vehicle because of higher transmission revs. This means that the car engine runs at higher speeds than the car itself. You may also find it very rough while shifting gears and as the problem worsens, you will find it unbearable to change the car into higher gears. This means that the vehicle’s transmission will eventually engage into overdrive very late.

Why this symptoms occur?

Because the transmission of your car can only shift smoothly with the help of a healthy speed sensor. This sensor counts the number of internal revolutions in the transmission. Consequently, the control unit of the transmission receives the data then makes the necessary adjustments after calculating the rotational speed. Unfortunately, it is impossible to repair the transmission speed sensor and immediately it becomes faulty, you have to discard it and replace it with a new one. A professional mechanic should help you examine and diagnose the speed sensor system of your vehicle even though the symptoms may seem similar in all cars.

  • Speedometer Malfunction

Once the vehicle’s speedometer stops functioning all of a sudden, this will clearly indicate that the speed sensor has become defective. The malfunctioning speed sensor means that the speedometer will not have the ability to read the speed of your car. This is very risky because you will drive without knowing the exact speed that your car has registered. This can land you in trouble with the authorities or even cause unnecessary and avoidable accidents.

  • DTC or Engine Code Light On

Furthermore, sometimes the check engine light may light up recurrently and periodically as you accelerate without any good reason. And commonly the code is P0500 (Vehicle Speed Sensor Fault Conditions). To check what the code is, you should use diagnostic tool or car OBD scanner.

Read also: The Reasons Why Your Car Engine Cranks But Wont Start

Many problems can arise if your vehicle has a faulty speed sensor. Indeed, a car that shows the symptoms of a worn-out speed sensor can bring about other related symptoms to other parts of the car, such as a faulty throttle position sensor or even a malfunctioning coil pack. Faulty speed sensor symptoms comes with some common characteristics that can affect your car engine and its related components.

And finally, any of the above speed sensor symptoms should prompt you to take your vehicle to professional car dealers or trustworthy mechanics so that they can run a computer diagnostic on your car to identify the faults. Even though some of the above symptoms may point towards a malfunctioning transmission, it is advisable to visit a repair shop having the best computer diagnostic equipment even before visiting a repair shop specializing on speed sensors to ascertain the real problems.



  1. I have a 2000 dodge neon and when you have it started and your foot on the patel and take it off it shunts off and the rpm gauges dont work i need help.

  2. I have a 91 ford f150 automatic it will run good then it will get where it will not pull park it for 2 days and it will run good again

  3. i have a 2004 mercedez c240. My gear will not change even after a long drive i have changed my faulty speed sensors but the problem still remains. do i also change the back axle shaft.

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