Park Assist Blocked: Meaning, Causes (& Repair Cost 2022)

The Park Assist feature of your car is indeed fantastic and very modern! It’s an automatic parking assist that enables you to park with higher accuracy by using its guiding system technology that competes with ultrasonic and various camera-based alternatives. When the “Park Assist Blocked” notice appears on your dashboard, your parking assist feature is no longer effective. This article deeply explains the symptoms of a bad parking sensor and the causes of the park assist blocked.

What does Park Assist Blocked Mean?

Park Assist Blocked is a warning that you get when the car’s parking assist system cannot function correctly. This means that the sensors are not working properly, and this can cause a problem for the driver, who may not be able to park the car without damaging it.

Park Assist Blocked

Park assist is an invaluable feature, so if you get this warning, it’s important that you get your vehicle looked at by an authorized mechanic as soon as possible. This technology intends to help drivers with parking by delivering audible and visual clues.

The most common reason you’ll see the message “Park Assist Blocked See Owners Manual” is that the ultrasonic sensors are not clean – likely from a build-up of dirt, mud, ice, snow, or slush.

Once this system malfunctions, it’ll be challenging to park your car correctly unless you’re a hard-core driver and can park like a boss. In rare instances, it might be impossible to park your vehicle perfectly.

The “Park Assist Block” notification serves as a reminder to be extra cautious while parking your automobile.

How does Parking Sensor Work?

You activate the parking assist system by pushing your vehicle’s park assist button when you’re in a parking lot or stop-and-go roadway.

working of parking sensor

Numerous automobiles may use their park assist sensors to seek a parking spot while you drive slowly.

When backing the car, the parking sensor uses the principle of ultrasonic waves. The ultrasonic sensor installed on the rear bumper sends ultrasonic waves to the obstacle and reflects the sound wave, calculates the actual distance between the car body and the obstacle, and then prompts the driver to stop.

When the car is in R gear, the parking sensor will automatically start. Through the controller, the ultrasonic sensor at the rear bumper controls the ultrasonic emission. The ultrasonic wave is reflected by obstacles, and the ultrasonic sensor receives the reflected ultrasonic wave and sends it to the amplifier circuit.

The ultrasonic sensor calculates the propagation speed in the medium by using the time from the transmission of the ultrasonic signal to the reception of the echo signal. The data is processed by the single-chip microcomputer, and then the distance and direction of the obstacle are displayed on the display to remind the driver to operate in time.

Types of Parking Assists

If the parking assist is blocked, it will not be able to detect objects in your path, and you may end up hitting something.

Following are two types of parking assists:

1) Electronic Parking Assist

This type of parking assist uses electromagnetic waves to detect the distance of objects in your path. They are placed on the outside of the car and may be visible as small, round sensors.

They alert the driver by displaying the distance to an obstacle on a screen or dashboard display.

2) Ultrasonic Parking Assist

This type of parking assist uses sound echo to detect and calculate the distance of objects in your path.

They are placed on the bumper of the car to ensure acoustic waves can travel uninterrupted. They alert the driver by beeping the alarm when an obstacle is detected within a certain range.

Causes Why Parking Assist Stops Working

In the majority of the cases, the Park Assist Blocked alert comes because of a defective parking assist sensor. 

Following are the most common causes of Park Assist Blocked:

  1. Damaged Bumper
  2. Washing the Car
  3. Low Battery
  4. Off-Road Driving
  5. Damaged Fuse
  6. Extreme Weather
  7. Damaged sensors
  8. Trailer Hitches & Tow trailers
  9. High Speeds
  10. Bad PCM

1) Damaged Bumper

If you own a modern car, you must know your vehicle carries modern features, like parking sensors. The parking sensors are located on the bumper of your car. When the bumper is damaged, the sensors can become dislodged or damaged. This may be caused by a minor problem or a more serious car accident.

A visual inspection will help determine if the parking sensors are damaged. You can tell if your car got hit from behind by a car or if you hit something while parking.

2) Washing the Car

Washing the car can trap moisture inside the parking sensors. This moisture can cause the sensors to corrode and eventually fail. To correct this, allow ample time for the parking sensors to dry. You can use a cloth or compressed air to speed up the drying process.

3) Low Battery

If your vehicle suffers from a low or weak battery, your park assist might not operate correctly or not operate at all. This could hinder your car’s capacity to park correctly using the system and might create issues with the vehicle’s other safety functions. It’s crucial to check the health of your battery for the proper functioning of your car’s safety features.

4) Off-Road Driving

With the summer just around the corner, most drivers will start taking their pride in a dirty ride: off-road driving. For those who are unaware, off-roading will result in a lot of dirt and mud build-up on your car’s body panels, especially in the lower area.

Off-road driving can cover the parking sensors with mud and dust. This will obstruct the view of parking sensors. A visual inspection of your vehicle will quickly identify if this can be the root cause of your problem.

The fix for this problem is easy; all you need to do is clean your car, and the warning message will go away. However, if the warning persists on your instrument cluster, then keep reading to see what else can cause the issue.

5) Damaged Fuse

Once the fuses are damaged, your parking aid system may fail to function. Among the most significant factors to address concerning electrical fuses is their effect on park assist systems.

Poorly built or produced electrical fuses could create operational issues, false alarms, or even total system breakdowns in specific systems.

6) Extreme Weather

Harsh weather conditions are capable of rendering parking sensors inoperable. In most cases, several drivers claim that their parking sensors ceased functioning after a snowstorm or severe rain. After the snow and ice melted, sensors would again work properly.

7) Damaged sensors

Park Assist sensors are typically located on the front and rear bumpers. So, if you hit your vehicle or someone hit you from behind, you’ll receive a Park Assist blocked on chevy or any vehicle model you own whenever you activate the system.

8) Trailer Hitches & Tow trailers

One of the common causes of a Park Assist blocked message on the instrument cluster is trailer hitches. Several drivers have complained on many automotive forums that their vehicles will disenable the Park Assist feature when towing a trailer.

It is important to note that after towing a trailer, the Park Assist will still be disenabled until you remove the trailer hitch.

9) High Speeds

Although the speed of a car is extremely slow while backing up, some drivers have a more spirited driving style, reaching speeds that some might consider unsafe while reversing.

If you are in an open area and reversing the car at higher speeds, it might cause your parking sensors to stop working. Most parking sensors stop working once the speed of the car exceeds 8 km/h or 5 mph.

This should be a temporary warning, and the message should go away as soon as you start moving forward. If the warning is still there, try restarting the car. If this did not solve the issue, there might be something else causing the warning message to appear.

10) Bad PCM

The powertrain control module (PCM) is the brain of your car. It receives information, processes it, and transmits the data to various systems. If it malfunctions, it’ll trigger and display several false pieces of information.

It can display a Park Assist blocked message on your dashboard when everything is working fine. However, this is unlikely, but it does happen.

Read More: Bad PCM Symptoms and Causes

Importance of Parking Assist

The Park Assist has the following importance:

1) Avoiding Accidents

Park Assist can also help you avoid accidents. If you are unfamiliar with an area or are trying to park in a tight spot, the parking assist can be a lifesaver.

2) Save Time

In addition to convenience, Park Assist can also save you time. If you are running late for an appointment or meeting, being able to find and park in a spot quickly can be a lifesaver.

3) Safety

Park Assist can also improve safety. If you are parking in a dark or dimly lit area, the parking assist can help you avoid hitting something or someone.

4) Convenience

Park assist can make parking much easier and faster. If you are in a hurry, the last thing you want to do is spend time looking for a spot and then trying to park.

Symptoms of a Bad Parking Sensor

As the parking sensor goes bad, it gives one of the below-given symptoms:

  1. Beeping Sound: When you hear a beeping sound when you engage park assist, it could be a sign that something is blocking the sensors.
  2. Sensors Not Working: If your Park Assist sensors are not working, it could be a sign of a problem with the sensors themselves or the wiring.
  3. Erratic Operation: When your Park Assist engages and disengages erratically, it could be a sign of a loose connection or a problem with the park assist sensor.
  4. Failure to Engage: This is when you press the button to engage park assist, but it doesn’t turn on. There could be a problem with the park assist switch, the fuse, or the park assist module.
  5. Visual Inspection: You can tell a parking sensor is damaged by visually inspecting it.
  6. Adaptive Parameters: The adaptive parameters generated by your parking sensor won’t display on your reverse camera screen or will point in the incorrect position.

How to Reset Park Assist?

Before going to a professional mechanic, there are a couple of steps below you can do to reset your park assist on Acura and Honda vehicles once you see the park assist warning in your driver information center or dashboard.

  1. Switch the vehicle to the ON position
  2. Wipe clean your front and rear park assist sensors thoroughly located on your rear and front bumpers.
  3. Click the Park Assist button ten times within ten seconds
  4. Turn off the ignition
  5. Turning the ignition on and off might help in some situations.
  6. You could try pressing the rear park aid to disable the button, then enable it afterward.
  7. Wait for ten to fifteen seconds and see if it will work.

How to test a Park Assist Sensor?

Follow the below-given steps to test your vehicle park assist sensor:

  • Remove all the parking sensors
  • Get your multimeter and switch it to 2000k ohms.
  • Locate the numbers on the terminal pins. There are three pins that are labeled 1,2,3. If you can’t see the numbers, use your phone camera for a better view.
  • Place the red multimeter probe on the no.1 pin and the black probe on the no.2 pin.
  • Note the results
  • Return the switch to 20k ohms.
  • Test the pins again by placing the red probe on no.1 and the black on the no.2 pins
  • At 20k ohms, you should have around 10.

Note: If you don’t have any numbers on both 2000k and 20k, it shows the Park Assist switch is bad. But if you have around 800-900 on 2000k settings and less than 9.7 on 20k, the sensor is questionable. So, get a new sensor and replace them. 

How much is it to fix a Parking Sensor?

The replacement cost of the parking sensor varies according to the labor cost and the model of your car. The average replacement cost of the parking sensor is from $490 to $1400.  

Other sensors like MAP sensorMAF sensor, and O2 sensor would cost you below $2900. But the reason behind the expensive replacement of parking sensors is that there isn’t one parking sensor in the bumper.

There are multiple sensors in it. So, you have to replace all sensors if the bumpers are damaged.

FAQ Section

What is Park Assist?

Park assist is a safety feature in newer cars that assists a driver in locating a parking space and safely parking the vehicle. If the Park assist malfunctions or is not working as it should, your car computer will trigger Park Assist blocked on Silverado, or your respective vehicle dashboard will have a pop-up regarding this.

Where are Park Assist Sensors located?

The parking assist sensor is located at the rear bumper of the vehicle. You can determine where it is by searching for a black or gray piece on the back of the bumper.

Some sensors are painted to match the color of the car, and others are in black or gray plastic housing. Usually, they’re located in a central location in the middle of the bumper and near the bottom, but you can find them by looking for a small circular piece about two inches across that sticks out from the bumper.

Where is the Park Assist Blocker Message Appears?

The message “park assist blocked” usually appears on the information cluster of the vehicle, which is more commonly referred to as the dashboard.

Is Park Assist the same as Parking sensors?

Park assist and parking sensors are not the same things. Park assist is a safety feature, and parking sensors are an object that aids in this action. Park assist is an advanced function that handles the steering when you are parking the car, while you just have to control the gas pedal and braking of the car.

What are the causes of Park Assist Blocked message?

  • The system is faulty
  • The obstacle is too high
  • Park Assist is not activated
  • The distance between the obstacle and the vehicle is too large
  • The sensors are blocked

Why is my vehicle notifying Park Assist Blocked?

Park Assist Blocked notification could appear if your ultrasonic sensors aren’t thoroughly cleaned. Keep your vehicle’s rear bumper free of muck, dust, snow, and mist.

What does park assist blocked mean on a GMC?

Just like other vehicles, if a GMC says Park assist blocked, the ultrasonic sensor is bad or not clean. The sensor should always be clean to function properly. That’s why it’s necessary to wash your car regularly. And when washing is not an option, locate and clean the sensors on your vehicle.

How to Clean Parking Sensors?

  1. Fill a bucket or bowl with warm water and add the advised amount of car shampoo.
  2. Dunk the microfibre cloth in the water solution and rinse. Be careful to gently remove any additional dirt that is on the cloth, as you don’t want to drag that around the surface of your car.
  3. Use the damp microfibre cloth to wipe the dirt off the parking sensors gently. Use a circular motion with the tip of your finger to ensure adequate coverage and dirt removal.

Can you replace one parking sensor?

You only need to disconnect the sensor, remove it from the bumper and replace it with the new one. If you have bought the right one, the new sensor should fit right into place, and the whole process should not take more than a couple of minutes.

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