4 Ways to Fix GMC Park Assist Not Working

GMC’s Park Assist technology helps drivers in avoiding collisions during low-speed parking maneuvers by using ultrasonic sensors in the front and rear bumpers. These sensors detect objects up to 6 feet behind and 4 feet in front of your vehicle when you’re driving at low speeds. However, sometimes you may encounter issues with your GMC Park Assist not working properly, becoming a concern for many drivers.

Before jumping to conclusions, it’s important to first identify possible causes of this problem, as they can range from faulty sensors to issues with your vehicle’s electrical system. In the following paragraphs, we will provide you with helpful insights and possible solutions to help you get your park assist system back up and running.

Common Issues With GMC Park Assist

Sensor Problems

One common issue with the GMC Park Assist system, particularly in models like the GMC Sierra, Cadillac Escalade, and Buick Enclave, is related to faulty sensors. These sensors can fail or become less accurate due to corrosion, physical damage, or loose connections. In such cases, you may need to check each sensor individually, either by listening for sounds emanating from them or by inspecting them visually for any damage.

Additionally, ensure all connections are secure. Regular maintenance can help prevent these sensor issues and keep the Park Assist system functioning optimally.

Blocked Park Assist

Another common issue with the Park Assist is when the system becomes blocked. This can happen if dirt, debris, or ice accumulates on the rear bumper or around the sensors. The system may display a “Park Assist Blocked See Owners Manual” message on the instrument cluster. In this situation, it’s crucial to inspect your rear bumper and clean off any dirt or debris that may be obstructing the sensors. Be mindful of this issue when driving in adverse weather, off-road conditions, or after visiting a car wash.

Malfunctioning or Erratic Operation

Lastly, your GMC Park Assist may experience problems with malfunctioning or erratic operation. These can stem from damaged bumpers, problems with the vehicle’s electrical system, or a combination of sensor and bumper issues. In any case, it’s crucial to identify and address the root cause to ensure the system functions properly.

Possible reasons for erratic operation include extreme weather conditions, high-speed driving, or other environmental factors. Be cautious when relying on the Park Assist system in such situations, and always use your judgment to assess the safety of any parking situation.

Remember to follow your vehicle’s owner’s manual for instructions on troubleshooting and maintaining the Park Assist system. Regular maintenance and addressing issues promptly will help ensure your Park Assist continues to provide safe and accurate assistance for your parking needs.

Resolving GMC Park Assist Problems

Resetting the Park Assist System

To reset the park assist system in your GMC, locate the fuse box, usually found in the engine compartment. Remove the fuse labeled “Parking Assist” or “Park Assist” and wait for about one minute before reinserting it. Start your vehicle, and the parking assist should be reset.

Checking for Physical Blockages

Inspect the rear bumper area for any dirt, debris, or objects blocking the park assist sensors. Clear away any blockages and ensure the sensors are clean. Also, check the park assist sensor bezel(s) in the bumper hole for proper mounting. Incorrectly mounted bezels can lead to sensor grounding out or becoming squeezed.

Switching the System On and Off

Ensure that the park assist system is enabled. Press the park assist button (also called the automatic parking assist button) located on your dashboard or center console. If the system is off, a DIC (Driver Information Center) message such as “Service Park Assist” or “Park Assist Blocked” may display. Press the button once more to turn the park assist system back on.

Replacing Faulty Sensors

If you still experience issues with your GMC’s park assist after trying the previous steps, you may have a faulty sensor. Check the sensors with a microphone or stethoscope while someone puts the vehicle in reverse. Listen for any sound from the sensors, as a lack of sound may indicate a faulty sensor or a loose cable connection. If necessary, visit your dealer for a proper diagnosis and replacement of any malfunctioning sensors.

Frequently Asked Questions

Why is my GMC park assist not working?

There are several potential causes for your GMC park assist to malfunction. It could be due to a faulty sensor, a blown fuse, or an issue with the wiring harness. To start troubleshooting, make sure your vehicle is clean and clear of any dirt or debris that could obstruct the sensors. If the issue persists, you may need to reset the parking assist by locating the fuse box and removing and reinserting the “Parking Assist” or “Park Assist” fuse.

How do I turn off the park assist feature on my GMC?

You can disable the park assist system in your GMC vehicle using the vehicle settings menu, by pressing the park assist button, or by turning the steering wheel while the feature is active. For more information on how park assist works and how to turn it off, visit the GMC vehicle support page.

How do the ultrasonic sensors on my GMC’s park assist system work?

The park assist system in your GMC vehicle uses multiple ultrasonic sensors located on your front and rear bumpers. These sensors are able to detect objects up to 6 feet behind your vehicle and up to 4 feet in front of your vehicle when you are driving at low speeds, helping you avoid potential collisions during parking maneuvers. For more information on how the sensors work, check out this explanation on park assist technology.

How do I know if a park assist sensor is faulty?

A faulty park assist sensor may cause the system to provide inaccurate or no warning at all when there are obstacles nearby. If you suspect that a sensor is faulty, you should first clean the sensors to ensure there isn’t any debris or dirt interfering with their performance. If the issue remains, you may need to consult a professional technician to diagnose and replace the faulty sensor.

Remember, staying informed on your vehicle’s features and maintaining its components can help ensure a safer and more enjoyable driving experience. Keep these tips in mind as you troubleshoot and maintain your GMC’s park assist system.


It’s important to address the issue of your GMC Sierra’s Park Assist not working. To resolve the problem, try resetting the feature by locating the fuse box and removing the “Parking Assist” or “Park Assist” fuse. Wait for a minute, then reinsert the fuse and restart your vehicle. If the problem persists, consider checking the sensors or consulting a professional for further assistance.

  • Eric Williams

    I'm the founder of Daily Car Tips. I wrote articles in the automotive industry for more than 10 years, published in USA and Europe. I love sharing my knowledge and insights with fellow enthusiasts. Join me on this journey as we explore the exciting world of cars together!

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