What is a parking space detection sensor: How does it work?


Parking space detection sensor for cars is one of the indispensable accessories today. Especially for new drivers and car owners, the space sensor is a device to help protect your car, protect yourself and those around you.

parking space detection sensor

Table of contents

  • What is space sensor?
  • The use of the space sensor
  • How does space sensor work?
  • Types of space sensors
    • Ultrasonic sensors
    • Radio frequency sensor
    • Infrared sensor
  • How to replace the space sensor for a car
    • Step 1: Identify faulty sensor
    • 2: Remove the faulty sensor
    • Step 3: Replace the sensor

Let’s find out what you need to know about this device!

What is parking space detection sensor?

The parking space detection sensor for cars is a device mounted on the rear of the vehicle, with the function of emitting a warning signal of collision danger when the driver reverses the vehicle.

Set of space sensors for cars

The type of sensor mounted on the rear of the vehicle is a short distance sensor. It sends out a signal whenever the vehicle’s distance from the rear obstacle exceeds 6m. This distance is calculated by the speed of the vehicle.

The long distance sensor is a blind spot sensor and is usually located in the front of the vehicle. A simplified version of the sensor emits a signal only when it detects any vehicle or object in the blind spot ahead.

The use of the parking space detection sensor

Car space sensor is very useful when parking

Parking space detection sensor are one of the most important and expensive parts of an automobile. It can detect almost any object that exists inside or outside the car. The space sensor helps the driver to easily detect dangerous situations when reversing, thereby avoiding collisions or accidents those are not visible through the rearview mirror. 

How does space sensor work?

The parking sensors common by car manufacturers can vary, but they always have some common ground in mechanics. Basically, they all work using one of 3 main methods:

  1. Vibration method
  2. Radio frequency method
  3. Infrared method

Types of space sensors

The main types of space sensors include ultrasonic, microwave, infrared, laser and radio frequency radars. However, infrared sensors are the most commonly common.

Infrared sensor is the common type on the market

Ultrasonic sensors

Ultrasonic sensors use sound to locate objects. There are three types of ultrasonic sensors: CW, CCW and CW CCW sensors. Each type of parking space detection sensor detects an object by emitting a series of ultrasonic signals. Objects reflect or bend ultrasonic signals, leading to the activation of sensors on the vehicle. With this mechanism, the ultrasonic sensor is more effective in locating the object.

Vibration sensors are similar to ultrasonic sensors. However, it only vibrates for a short period of time and the power is low. This method is often common to determine the direction of movement of objects, such as pedestrians and bicycles.

Radio frequency sensor

Radio frequency (RF) sensors emit radio waves with extremely high frequencies, typically 20,000-22,000 Hz, to transmit and receive reflected signals. 

parking space detection sensor 2021

The advantage of RF sensors is that they are not affected by atmospheric conditions and electrical noise. However, this type of sensor is prone to false activation, and has a high cost.

Infrared sensor

Infrared sensors are one of the most common types of parking sensors common by car manufacturers. Similarly, infrared sensors operate in the infrared spectrum, usually in the 810-1250nm wavelength, which can sense changes in temperature. When the vehicle moves close to the parking space detection sensor, the vehicle’s temperature changes. This activates the sensor and sends a signal to the control module.

There are two types of infrared sensors. Passive infrared (PIR) sensors only sense temperature changes of objects, such as the body temperature of passengers and cars. The active infrared (AI) sensor not only senses temperature changes, but also detects signals reflected from the subject.

Infrared sensors are more accurate than ultrasonic sensors. It is also resistant to weather and temperature conditions. However, it requires a range of at least 1m for accurate object detection.

How to replace the parking space detection sensor?

Car space sensor is easy to install by you

Step 1: Identify faulty sensor

The way the parking space detection sensor works is the same as any other parking sensor in a car. Once it detects a vehicle or an obstacle behind it, it vibrates the sensor wire and turns on the lights on the dashboard.

Step 2: Remove the faulty sensor

To change the space sensor in a car, you must first locate the faulty sensor. This can be difficult as it is usually only determined after parking for a long time.

Start by looking for any signs of corrosion, especially on the leads running from the battery to the sensor. This means that the sensor’s power cords are damp. Corrosion will reduce electrical conductivity and alter vehicle performance. 

Also, check the connectors of the extension cords. If they are damaged or lose, you should replace them. 

Step 3: Replace the parking space detection sensor

Once a faulty parking space detection sensor has been identified, simply replace it with a new one. The price of the space sensor is not expensive and there are many different brands, usually in the range of $200. Please note that the type of space sensor is suitable for the vehicle’s sensor system when buying.

After the replacement test, be sure to wipe away any stains from the old sensor.


Although the space sensor is very useful, not all models have it installed. You can absolutely buy and install a new space sensor. The information in the article will help you understand more about space sensors for cars, so that you can choose the most suitable device for your vehicle.

How does parking sensors work?

If you choose parking space detection sensor, the principle of operation is usually described for each individual model. But in general, the algorithm of action is similar for many devices:

  • the sensory signal that forms around the car is reflected when it encounters an obstacle;
  • the sensor reflection signal is analyzed by the control unit;
  • the block gives the distance that remains to the barrier and determines the level of danger: for example, from green to red.

At the same time, it is important to know when buying front and rear parking sensors that all this happens in just a few seconds. That is, the driver essentially has no chance of accidentally colliding with foreign objects.

Summary parking space detection sensor

We hope we helped you figure out what parking space detection sensor is and how it works. Parking radar is a useful purchase for all drivers. To select the right model, consider the installation method, accuracy level, alert mechanism, etc. 

But even regardless of these factors, all high-quality models guarantee high accuracy and ease of use of the system, which makes it possible to avoid most of the problems during parking.

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