Park Assist Blocked – Meaning and How to Fix

Most cars nowadays have a technology called “Park Assist” that helps you when parking your car in a confined space. But, sometimes, a warning message on your dashboard says, “Park Assist Blocked.” So, what does it mean, and how can you fix it?

The most common cause for the “Park Assist Blocked” warning light is a build-up of dirt and mud on the ultrasonic sensor that blocks it from working. When this happens, do the following:

  • Step outside the car, check the parking sensors in the rear bumpers, and wipe them clean with soft tissue paper,
  • To reset the system altogether, disconnect the battery and toggle the Park Assist button on and off,
  • You can also try turning the ignition on and off,
  • Push the rear Park Assist “disable button” and then re-enable it again, and
  • Finally, you can ignore the Park Assist Blocked message by tapping the odometer stem, which may solve the issue.

Read on to learn more about the Park Assist Blocked message and how to fix it.

Park Assist Blocked – Meaning and How to Fix

park assist blocked

When the message “Park Assist Blocked See Owner’s Manual” pops up on your car’s dashboard, it alerts you that the system has been deactivated. There are many potential causes, such as:

  • Dirty ultrasonic sensors,
  • Low batteries,
  • Extreme weather, or
  • Bumper damage. 

Park Assist Blocked on Different Car Models

1. GMC

The Park Assist feature provides audio and visual cues to drivers to help them with parking. When this system fails, parking your car correctly won’t be easy unless you’re a hard-core driver with masterful parking skills. 

The “Park Assist Blocked” warning light is a gentle reminder to park your car with extra caution. Usually, the ultrasonic sensors are the main cause of the Park Assist Blocked message on a GMC. 

2. Chevy

When you have a defective parking sensor on your Chevy, the Rear Park Assist stops working, so Park Assist Blocked will show up on the dashboard. Before drawing any conclusions, test the sensor first to check whether it is the main cause.

Testing the sensor should take no more than one hour and thirty minutes. These are the steps to follow:

  • Take out each parking sensor,
  • Grab your multimeter and set the resistance to 2000k,
  • Find the pins with the numbers on them. There are three pins with the numbers 1, 2, and 3. Use the camera on your phone to get a clearer picture if you can’t make out the digits,
  • Affix the black multimeter probe to the no. 2 pin and the red multimeter probe to the no. 1 pin,
  • Then, switch back to 20k ohms,
  • Place the black probe on the no. 2 pins and the red probe on the no. 1 pin to test the pins once more,
  • For a positive result, you should have about ten at 20k ohms.

If neither 2000k nor 20k has any numbers, the Park Assist system is malfunctioning. Moreover, if you have 800-900 on 2000k settings and less than 9.7 on 20k, you will need to buy a new sensor.

3. Chevy Tahoe

Same steps as above, but ensure all the sensors are as far back as they can go. Just give them a good push from inside the bumper.

This is because the parking assist sensor is usually located in the rear bumper of a Chevy Tahoe. Look for a black or grey piece to pinpoint its location.

While some sensors are housed in black or grey plastic housing, others are painted to match the car’s color. You can usually find them in the center of the bumper, close to the bottom, but you can spot them by looking for a tiny, circular protrusion from the bumper about two inches across.

It only takes a few button presses to restart the Park Assist on a Chevy Tahoe. Your car will start when you turn on the ignition, so press and hold the button for a few seconds before you start driving the car.

You can find the button on the dashboard or center console between the front seats.

If unsure, check your owner’s manual to ensure you are doing the right thing. 

4. Chevy Traverse 

You can do a few things if Park Assist isn’t working properly on a Chevy Traverse:

  • Clean the sensors with a warm, moist cloth.
  • If this does not fix the issue, you can take your car in for maintenance so that they can check and test the sensor for you. Inspect the wire harness, fuse box, and circuit breaker. 
  • If the problem persists, check to see if the parking brake is in the right position and if your car’s electrical connection is secure. Push the pedal until you feel resistance at the top to ensure you are safe.
  • Then, slowly release it several times. It might be time for a new parking brake switch or actuator motor if it doesn’t work.

The price of sensors for a Chevy Traverse can be anywhere between $100 to $450. Replacing the camera can cost $645 up to $660.

Hill Start Assist Not Available for Ford

10 Causes of Park Assist Blocked Message

park assist blocked see owners manual
Chevy Traverse Off-roading

1. Ultrasonic Sensors

Your ultrasonic parking sensors might contain moisture or water after a car wash. Due to the sensor’s inability to read anything in front of it, this moisture will limit its functionality, and you end up with the “Park Assist Blocked” warning light on your dashboard.

2. Low Battery

Your park assist system may not function properly if your car has a low or weak battery. This can make it more difficult for your car to park using the system and might also interfere with some of the other safety features. 

3. Off-roading

Off-road driving could obstruct parking sensors with grit and gravel or, even worse, damage them with harsh shocks. This can affect your parking sensors’ visibility, so it is always a good idea to check them each time you go off-roading.

4. Extreme Weather

Parking sensors might become dysfunctional due to harsh weather conditions. Many drivers claim that their parking sensors stop working following a blizzard or heavy rain. 

5. Bumper Damage

Car makers usually place the parking sensors on a car’s front or rear bumpers. So, when the bumper gets damaged, your parking sensors will eventually stop working, too, and you will need to fix or replace them as soon as possible.

6. Wrong Steering Fluid

When you park, you use your steering. Your Park Assist will stop working if the steering does not have the right fluid. 

The fluid’s density must be the right one for your car. 

As you park, your sensors can measure the distance between your car and other objects. Additionally, make sure to check the fluid level periodically. When the level is low, add more.

How to Choose the Right Power Steering Fluid

7. High Speed

Your parking sensors can stop working if you are reversing your car quickly in an open place.

Usually, parking sensors stop working if your car is moving faster than five miles per hour. It will be a good idea to reverse at normal reverse speeds if you want to get the most out of your parking sensors.

8. Electric Fuse Blow

The impact of electrical fuses on park assist systems is probably one of the most important, frankly difficult, issues to overcome. 

If the fuses are damaged or malfunctioning, your park assist system will stop working, and this may result in wrong messaging, false alarms, or even complete system failure.

9. ECU Problems

If all is well and you still see the “Park Assist Blocked” message on your dashboard, you likely have some ECU issues.

The ECU acts like your car’s brain as it receives, processes, and sends signals in your car. So, chances are you will get annoying messages like “Park Assist Blocked” if there is a bug or technical issue with your car’s ECU.

10. Trailer Hitch

When towing a trailer, you typically receive a message that your parking assist is blocked or disabled. The main cause is usually the trailer hitch; you must take it off. Otherwise, you might still receive the “Park Assist Blocked” message even if you disconnect the trailer.

Again, what does park assist blocked mean? You’ll see the Park Assist Blocked on the dashboard when you have dirty ultrasonic sensors, making the parking assist feature ineffective.

How to Fix Park Assist Blocked 

park assist blocked chevy traverse

1. Test the Sensors

To ensure the sensors are working well, you should perform a visual check and a functional test.

Visual Check

Check the front parking sensors visually to ensure no dents in the bumper or fenders that can affect their ability to detect things. Take your car to a nearby dealership for repairs if you find any minor dings or cracks in these places.

Functional Test

Test the front parking sensors’ functionality by turning on your car and listening for beeps when an object is close enough to trigger them (usually around 6 inches). You may need to replace one or both of your front parking sensors if it does not beep when you go close to an item.

The power supply wires from each sensor may have loosened somewhere along the road. Turn off all the lights inside and outside your car, except the headlights, to test this.

After checking wiring connections, if there is still no beeping sound, there may be a problem with one or both of the wires running between them being bad. This means you should replace them depending on how much damage has been done. 

2. Disconnect the Battery to Reset the Park Assist System

Your car will fully restart when the battery is connected again after about 15 minutes. Even if you do a power pull in several different places around the car, it won’t retain any charge if you unplug the ECU. 

This is why it is best to calmly wait for a “safe” period when it’s vacant. Resetting the system while the battery is connected is not the best action. 

This is because the system suffers memory loss when you remove your battery. This includes the preset ratio, the right mixture of air and fuel, and the car’s shifting point.

3. Press and Hold the Park Assist Button for Long

This is the simplest fix of all. Press the Park Assist button on the car’s center console and hold it for a few seconds to turn the system off. When the Park Assist system is blocked, you will hear a long beep after releasing the button, say, 10 seconds or so.

4. Try Turning the Ignition on and Off

Turn off your car and then turn the key without actually starting your car. Press the Park Assist button, hold for about 10 seconds, and then switch the ignition off. 

Now, turn on the ignition and see if the “Park Assist Blocked See Owner’s Manual” still pops up on the dashboard.


What Is Park Assist?

It is short for Automated Parking Assistance. It uses guiding system technology to help the driver park more effectively, competing with ultrasonic and other camera-based features with greater and extraordinary advanced technology.

Park Assist enhances every parking experience by detecting parking spaces and barriers using front and rear park assist.

The primary mode will automatically control the vehicle by moving the steering wheel, but the driver will still control the brake, throttle, and gearshifts. It will allow you to drive out of a confined space easily.

What Does Park Assist Blocked Mean?

The warning light “Park Assist Blocked” appears on the dashboard when the Park Assist system of the car is unable to operate correctly. This is because the sensors are not functioning as they should, which can cause a big mess for the driver as they will not be able to park the car safely.

The leading cause for this is usually a dirty ultrasonic sensor, so clean them well with a soft, moist cloth. A low battery, harsh weather conditions, and bumper damage can also cause this Parking Assist Blocked message to show up.

How Can You Tell If a Parking Sensor Is Bad?

Your parking system will often signal warning lights even if there are no serious issues with your car. The adaptive settings of the parking sensor will ensure this happens.

Moreover, self-parking could work poorly if one of the parking sensors is damaged. So, you will need to perform a visual inspection to see what is wrong with the sensor.

How Much Does It Cost to Fix Park Assist Blocked on a GMC Sierra?

Assuming the parking sensor is the cause here, you can clean the sensor with a soft, moist cloth, and that will be it.

However, in some cases, you may need a mechanic to look at it and eventually repair it or replace it altogether. This can be a bit expensive, depending on the condition of the faulty parking sensor. 

A GMC Sierra’s average cost of repairing a faulty sensor ranges from $50 to $250. A single Park Assist sensor costs range from $20 to $75.

How Do You Turn Park Assist Back On?

Older car models have a Park Assist button behind the steering wheel on the dashboard. You can turn off and turn back on the park assist feature in such cars by pressing the button.

Other cars have it on the center console. If your car is a more recent model, you can always consult your owner’s manual for instructions on activating and deactivating the Park Assist feature.

Conclusion – How to Fix the Park Assist Blocked Warning Light 

Park Assist is an excellent feature that comes in handy when you park your car in narrow spaces. It enhances every aspect of your parking experience and allows you to drive out of a confined space.

However, this system may sometimes stop working, and a message “Park Assist Blocked” pops up on your car’s dashboard. 

This warning light will flash to let you know that the Park Assist system is no longer working and that you will have to drive more carefully now. There are many causes for this message, and we hope this guide has shed light on some of them.

For instance, a build-up of dirt and debris on the ultrasonic sensor will get it blocked and prevent it from functioning well. Luckily, fixing it is not rock-solid science, so here is what you can do:

  • Check and do a visual and functional test of the parking sensors in the rear bumpers,
  • Disconnect the battery and toggle the “Park Assist” button on and off to reset the system,
  • Try turning the ignition on and off,
  • Push the rear Park Assist “disable button” and then re-enable it again,
  • Ignore the warning light by tapping the odometer stem, which may solve the issue, but only do this as a last resort.

Read next:

Pros and Cons of a Manual Parking Brake