The Park Assist system of the vehicle is one of the most useful features of the vehicle. An automatic parking assist system that uses guidance system technology that competes with ultrasound and various camera-based alternatives to help you park more accurately. If the notification “Park Assist Blocked” appears on the car dashboard, it means your car’s parking assist feature is no longer active. This article describes 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 an alert you receive on your vehicle dashboard when your vehicle’s parking assist feature doesn’t work properly. It means that the parking sensor isn’t operating efficiently and can cause problems for drivers who cannot park their cars without a parking sensor.
The park assist is a very valuable feature. This feature is designed to assist drivers park by providing audio and visual signs. If you see the Park Assist Blocked warning light, have your vehicle checked by a certified mechanic immediately.
The dirty ultrasonic sensor due to the accumulation of slush, snow, ice, mud, or dirt is one of the major causes for the message “Park Assist Blocked”.
If this feature goes bad, it becomes difficult to park properly unless you’re a die-hard driver and know how to park like a boss. In some cases, full parking may not be possible.
The “Park Assist Block” warning light reminds you to be additional careful when parking.
How does a Parking Sensor Work?
When you are in a parking lot or on a parked street, pressing the Park Assist button of your car activates the Park Assist system.
Many cars use a parking assist sensor to find parking spaces when driving slowly.
When reversing the vehicle, your vehicle’s parking sensor works according to the ultrasonic waves principle. A parking sensor or ultrasonic sensor mounted in the back bumper emits and replicates ultrasonic waves at obstacles to measure the actual distance between the obstacles and the vehicle body and then encourage the driver to stop the vehicle.
The parking sensors are activated automatically when your car engages the reverse gear. Ultrasonic sensors in the back bumper control the ultrasonic emission via a control unit. The obstacles reflect the ultrasonic waves sent to the ultrasonic sensor, and the ultrasonic sensor further transfers these waves to the amplifier circuit.
Ultrasonic sensors measure the circulation speed in the medium by utilizing the time between the transmission of the ultrasonic signal and the reception of the echo signal. The information is managed by a single-chip microcomputer, and the distance and direction of obstacles are displayed on the screen to encourage drivers to take timely action.
Types of Parking Assists
When the parking assist feature is blocked, it cannot sense any object in its path, and your vehicle could bump into something. The parking assists have the following two types:
- Electronic Parking Assist
- Ultrasonic Parking Assist
1) Electronic Parking Assist
The electronic parking assist utilizes electromagnetic waves to sense the distance of an object in the vehicle path. This type of parking assist system is attached to the outside of the vehicle and appears as a small circular sensor.
It warns the driver by showing the distance to obstacles on your vehicle’s dashboard.
2) Ultrasonic Parking Assist
The ultrasonic parking assist utilizes sound reflections to sense and measure the distance of the object in the vehicle’s path.
It is mounted to the bumper of your vehicle and allows the sound waves to move unhindered. If the problem is detected within a specific range, an alarm will sound to warn the driver.
Causes Why Parking Assist Stops Working
- Damaged Bumper
- Off-Road Driving
- Low Battery
- Washing the Car
- Damaged Sensors
- Extreme Weather
- Damaged Fuse
- Trailer Hitches & Tow trailers
- High Speeds
- Bad PCM
1) Damaged Bumper
Modern vehicle models contain parking sensors. The parking sensor is installed on the car’s bumper. If the bumper is broken, your sensor may be displaced or damaged. Even a small issue or a serious car accident may damage the bumper.
In such a condition, you should perform a visual inspection to check if the parking sensor is damaged. You can tell if your vehicle was hit from behind by a vehicle or something else while parking.
2) Off-Road Driving
With the arrival of summer, most motorists begin to take their pride in a dirty ride: off-road driving. When you drive off-road, a large amount of contamination may accumulate in the vehicle’s body panels, especially on the underside.
When driving off-road, a lot of dust and mud may build up on your parking sensors. This blocks the view of the parking sensor. Perform a visual inspection quickly to check the dust and dirt on your parking sensors.
Fixing this issue is very easy. Just clean your car, and the Park Assist Blocked warning message will be gone. But if the warning continues to appear on the car dashboard, read on to find out what else could be causing the problem.
3) Low Battery
A low battery or dead battery is one of the major causes of the Park Assist Blocked.
Park Assist feature is highly dependent on the car battery. Park Assist may not work properly or at all if the vehicle’s battery is low or dead. This may prevent the car from being properly parked with the system and may affect other vehicle safety features. Checking the health of your battery is essential to ensure the efficient working of the vehicle’s safety features.
4) Washing the Car
Car washes may cause moisture to build up in the parking sensor. This moisture may cause corrosion in the sensor and ultimately lead to failure. Allow sufficient time for your parking sensor to dry to fix this problem. A cloth or compressed air can be used to accelerate the drying process.
5) Damaged Sensors
The damaged parking sensor is one of the major causes of a Park Assist blocked message. Parking assist sensors are usually installed on the rear and front bumpers. When someone hits your vehicle from behind, or you hit it yourself, you get a Park Assist Blocked message on your vehicle dashboard, which indicates that your parking sensors are damaged.
6) Extreme Weather
Bad weather condition is one of the main causes of a bad parking sensor. Most often, some motorists said that their parking sensors stopped working after heavy rain or a snowstorm. After the snow and ice melt, the sensor returns to normal operation.
7) Damaged Fuse
A blown fuse can result in the parking assist not working. One of the most important factors related to electrical fuses is their impact on the parking assist system. If an electrical fuse is poorly manufactured or installed improperly, it can cause operational problems in a particular system, false alarms, or even failure of the entire system.
8) Trailer Hitches & Tow trailers
The trailer hitch is a common reason for the message “Park Assist locked” on the dashboard. Some drivers have objected about their vehicles disabling the Park assist feature while towing a trailer.
Note that your Park Assist feature will be inactivated after towing a trailer until the trailer hitch is removed.
9) High Speeds
The car reversed very slowly, but some drivers adopt a more energetic driving style and touch high speeds that might consider hazardous to reverse.
Your vehicle parking assist sensors can fail when backing up at high speed in an open zone. Maximum parking sensors stop working at speeds above 8 km/h.
This is a temporary warning that may go away once your car starts moving forward. If the warning persists, turn off your vehicle and restart it. If this doesn’t solve the problem, there may be other reasons why you’re getting the Parking Assist Blocked warning message on your vehicle dashboard.
10) Bad PCM
The Powertrain Control Module (PCM) is considered the brain of the vehicle. It gets information from different sensors of your vehicle, processes this information, and sends data to different systems. If it fails, it will trigger different wrong warning lights on your car dashboard.
You may see the Park Assist blocked message on your dashboard if all goes well. Although this is very rare, it can happen.
Read More: Bad PCM Symptoms and Causes
Advantages of Parking Assist
Park Assist has the following advantages:
- Avoid Accidents
- Save Time
This feature also increases safety. When parking in dimly lit or dark regions, Park Assist helps you evade collisions with objects or people.
It makes parking easier and quick. When you’re in a hurry, you definitely don’t want to waste time searching for a parking space and then struggling to park.
3) Avoid Accidents
The parking assistant system helps to prevent your car from accidents. If you are new to the area or trying to park in a tight area, Park Assist can save your car from an accident.
4) Save Time
One of the major advantages of the parking assist sensor is that it saves your time. If you’re late for a meeting or appointment, the parking assist feature helps to find a parking place quickly.
Symptoms of a Bad Parking Sensor
As the parking assist sensor goes bad, it produces one of the below-given symptoms:
- Inspect Visually: A visual inspection can determine if the parking sensor is damaged. If the park assist sensor is damaged, replace it as soon as possible.
- Beeping Sound: The beeping noise is one of the common symptoms of a bad parking sensor. If you hear beeps when Park Assist is activated, this could indicate an object is blocking the sensor.
- Sensor Not Operating: If the parking assist sensor is not working, there may be an issue with the sensor or the wiring.
- Sensor Not activated: This is the situation when you try to activate the parking assistant by pressing the button but did not turn on. There may be an issue with the park assist module, fuse, or park assist switch.
- Inconsistent Operation: If the Park Assist system turns on and off inconsistently, you may have a loose connection or an issue with the parking sensor.
- Adaptive Parameters: The adaptive parameters produced by the parking sensors won’t show on the rear camera screen or will point to the wrong place.
How to Reset Park Assist?
If you see a Park Assist Blocked warning on your vehicle dashboard, there are a few steps you can take to reset the Park Assist on Honda and Acura cars before visiting a professional mechanic. Follow the below-given steps to reset the Part Assist:
- Turn the car to the ON position.
- Thoroughly clean the front and back parking assist sensors located on the front and back bumpers.
- Now click the Park Assist button 10 times within 10sec.
- Turn off the ignition switch.
- In some cases, it can be useful to switch the ignition switch on and off.
- Try to press the back parking assist to disable the button, and after some time, enable it.
- Wait 10-15 seconds and check if it works.
How to test a Park Assist Sensor?
Follow the below-given steps to test your vehicle park assist sensor:
- First of all, remove all parking sensors
- Change your multimeter to 2000k ohms
- Check the terminal pin numbers. Three pins labeled 1, 2, and 3. If you can’t see the numbers, use your phone’s camera to get an improved view.
- Put the red multimeter probe on pin 1 and the black probe on pin 2.
- Pay attention to the results
- Set the multimeter switch back to 20k ohms.
- Put the red probe on pin 1 and the black probe on pin 2 and test the pins again.
- At 20k ohms, it should be about 10.
Note: If the numbers 20k and 2000k are missing, the Park Assist switch is defective. However, if it’s about 800 to 900 at the 2000k setting and below 9.7 at the 20k setting, then the sensor is bad. So, get a new sensor and replace it.
Parking Sensor Replacement Cost
The replacement cost of the park assist sensor varies according to the labor cost, your living area, and the model of your car. The average replacement cost of the parking sensor is from $470 to $1500.
Other sensors like MAP sensor, MAF 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.
What is Park Assist?
Park Assist is a new car safety feature that helps drivers find parking spaces and park safely. If the parking assist system fails or is not operating properly, the powertrain control module (PCM) will disable the Silverado’s parking assist system or display a pop-up message on the respective vehicle’s dashboard.
What are the causes of the Park Assist Blocked Message?
- Faulty Park Assist system
- Faulty parking sensors
- Damaged bumper
- Off-Road driving
- Low battery
- Damaged sensors
- Extreme weather
- Damaged fuse
- Trailer Hitches & Tow trailers
- High speeds
- Bad PCM
Where is the Park Assist sensor located?
The Park assist sensor is located on the vehicle’s rear bumper. You can find it by looking for the gray or black area on the back of the bumper.
Some Park Assist sensors are painted to match the color of your car, while others come in gray or black plastic housings. They’re usually centered near the center and bottom of the bumper, but you can find them by looking for a small round piece about 2 inches wide that protrudes from the bumper.
Where is the Park Assist Blocker Message Appears?
The “Park Assist Blocked” message is usually displayed on the vehicle’s information cluster, known as the dashboard.
Is Park Assist the Same as Parking Sensors?
Park assisting sensor and Park Assist are not the same. Park assist is a safety feature, and parking sensors are the things that help in this action. Park Assist is the latest feature that manages to steer when parking, so you only have to control the accelerator and brakes.
Why is my vehicle notifying Park Assist Blocked?
If the ultrasonic sensor has not been thoroughly cleaned, you may receive a notification that Park Assist blocked. Keep your car’s back bumper free of dirt, dust, snow, and fog.
How to clean Parking Sensors?
- Fill a bucket or bowl with warm water and add the advised amount of car shampoo.
- 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.
- 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.