Symptoms of Bad Vehicle Speed Sensor


Symptoms of Bad Vehicle Speed Sensor

Vehicles are complicated pieces of machinery, and it is important for you to take care of every part of the vehicle. In order to ensure that it is in

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Vehicles are complicated pieces of machinery, and it is important for you to take care of every part of the vehicle. In order to ensure that it is in proper condition.

One of the most essential parts of a vehicle is the speed sensor (VSS). It is also referred to as the transmission speed sensor or output shaft speed sensor. It is a small but important device because it determines how fast your vehicle is going.

There are several essential parts and features of this device. First, the VSS produces low voltage signals that are related to one or more computers that are referred to as the control modules. A falling speed sensor can affect more than just your vehicle’s speedometer. Yes, if your sensor is broken, this can hinder your ability to drive the vehicle safely.

So, it is essential to know what the symptoms of the bad speed sensor are so you can immediately repair it.

What is a Speed Sensor?

Have you ever gone down the road and noticed your speedometer shows a different speed than the speed of your vehicle is? While driving, we usually think we are not driving at a good speed and this could be because of a faulty vehicle speed sensor.

The vehicle’s computer calculates how fast you’re traveling based on information from the vehicle’s speed sensor. If it senses that the speedometer is incorrect, or if the vehicle’s speed signal is interrupted for any reason. The vehicle’s computer will override this with its own calculation of how fast you are actually moving.

Speed sensors can be found in almost all vehicles. Even if you buy from used cars for sale in Tanzania, you have to look after its speed sensor. They provide information about your rate of speed to the powertrain control module (PCM). The PCM uses this information to calculate vehicle speed for the speedometer and cruise control. If a speed sensor becomes faulty, your speedometer will show inaccurate speeds, and your cruise control system may not function properly.

A faulty speed sensor can also lead to incorrect engine idle speeds, traction control problems, electronic stability problems, and ABS brake system problems. Therefore, people who rely on their vehicle’s speedometer to monitor their driving speed need to have this problem checked out by a mechanic right away if they notice incorrect readings.

Reasons to Monitor the Speed Sensor

You need to monitor the health of your vehicle as it requires regular maintenance to ensure long-lasting quality. For example, suppose a vehicle is not properly cared for. In that case, it can lead to significant internal damage leading to costly repairs or even replacement of the entire vehicle because the VSS might not show you proper results.

Once diagnosed, many issues can be repaired for less than the cost of a new car. As the incorrect speed sensor can also lead to accidents. Yes, symptoms of a bad vehicle speed sensor can be scary, but their presence doesn’t have to lead to an expensive repair bill. If you have concerns or questions about any symptoms your vehicle is presenting, contact a trusted mechanic as soon as possible.

It is important when diagnosing the symptoms to consider where you take your vehicle for service. Many mechanics will do unnecessary repairs to make you think they are fixing the problem. It is important that you trust your mechanic and question repairs costs before work begins if you feel unsure about his work

The cost of the speed sensor depends on the model of your vehicle. So, always visit the mechanic you trust in order to avoid any inconvenience. Moreover, you already know that a damaged speed sensor can result in accidents, so don’t worry about the cost.

If you have questions or concerns about the work being done on your vehicle, trust your mechanic and do not be afraid to ask questions. Keeping cars in good working order is a necessity for all drivers. So if you suspect any of these symptoms, it’s important that you take action and contact a trusted mechanic as soon as possible.

Symptoms of a Poor Vehicle Speed Sensor

Many vehicles use the wheel speed sensors in all 4 of the wheels as inputs for cruise control functions, traction control, ABS braking systems, stability systems, and speedometers. If one of these sensors is not working properly, it can cause several problems.

So, here is the list of the common symptoms that you should be mindful of.

Ø Incorrect Speedometer Readings

Symptoms of a bad vehicle speed sensor include an incorrect display on your vehicle’s speedometer or odometer. Your car may indicate that you are driving much slower than you actually are; this could be due to a faulty speed sensor on your front axle. However, suppose the faulty speed sensor is on the rear axle. In that case, you could experience the opposite problem. And find that your vehicle’s speedometer or odometer indicates a higher rate of speed than your actual rate of speed.

Ø Transmission Issues

Vehicle speed information is relayed on the vehicle speed sensor used by the transmission control module or the power train module to determine the shift timings. Thus, a failed speed sensor will directly impact the automatic transmission operation.

Moreover, the transmission problems could exhibit problems such as delays in the shifts or limited operations of the gear.

Ø Inability to Engage Cruise Control

The vehicles will be disabled by the powertrain control module (PCM) as soon as it receives the information from the vehicle speed sensor. The reason is that the system needs the sensor’s data for the purpose of keeping your vehicle running at a constant speed.

So, if notice this symptom then do visit your mechanic so he can identify the issue for you.

Ø Lack of Torque

The torque converter gets activated with the pre-programmed speed. Thus, if the speed sensors give inaccurate readings. The transmission torque converter will not be able to apply the clutch to form the mechanical link between the engine and the transmission.

This can result in reduced fuel economy and the problem of overheating as well.

Ø Triggered Engine Light

You should suspect that your speed sensor is not working when you notice that your engine light is triggered. Another warning includes that the dashboard’s traction control systems might also appear.

If you have doubts. Do connect your vehicle to an OBD-II scan tool to confirm whether the error points towards the malfunction or not.

Ø Startup Problems

Do you know that if your speed sensor is not working properly, your vehicle will not even start? This is one of the most common problems that can occur. If the electric control unit of the vehicle does not know the crankshaft’s position, it will not even start.

So, get your vehicle checked immediately if it doesn’t start.

Ø ABS Light

If you have a vehicle that consists of an ABS system, then a bad vehicle speed sensor will trigger its ABS light. Thus, most vehicles cannot function properly if they do not receive a good signal from the four-wheel speed sensor.

So, next time if your ABS light gets illuminated, you should understand that your speed sensor is not working properly.

What Causes the Speed Sensor to Fail?

The causes are as follows:

  • When the magnetic part of the sensor gets damaged over time, this results in the faulty speed sensor.
  • Some internally damaged speed sensors can also result in the abnormal output of the speed sensor.
  • If your car is involved in some accidents, then there are chances of damage to the speed sensor.
  • Also, if you don’t maintain the health of your vehicle then this also results in the failure of the speed sensors.
  • Some electric faults in the speed sensor also hinder its ability to show the readings properly.


Several problems might arise if you do not pay heed to the malfunction of the speed sensor. First, you should take care of your vehicle because if your speed sensor is damaged, then this can hinder your ability to drive the vehicle safely.

If your vehicle’s speed sensor is not working properly, you should always be careful about the symptoms mentioned above. So, get your vehicle checked immediately if you want to keep your vehicle in good condition.