What Does Pre-collision Assist Unavailable Mean?

With each passing year, the technology in cars keeps getting better and more complex. The new innovations that have successfully been incorporated in new cars include proximity sensors that warn drivers of nearby people and objects and pre-collision assist. 

Pre-collision assist is installed in cars for the primary purpose of preventing collisions and accidents. However, this system is likely to get faulty due to some reasons. If that is the case, you will receive the ‘pre-collision assist not available sensor blocked’ signal. This signal simply means that the sensor that reports to the pre-collision assist system is currently blocked. 

This article focuses on the pre-collision assist system, how it works, instances that could lead to blocking of the sensor, and how to solve it.

What Is the Pre-collision Assist System?

What does pre-collision assist not available sensor blocked

Nowadays, vehicles come installed with several driving aids to play the role of driver assistance systems and improve safety while driving. These driving aids also play the important role of guiding the driver in different occasions and surroundings.

The systems employ radar and ultrasonic sensors to monitor the surroundings whenever the vehicle is in motion. The Pre-collision assist is one such system. 

As the name suggests, this system is tasked entirely with helping you prevent collisions. Therefore, it relies on sensors and cameras which play the role of assessing the situation around you and taking the necessary action.

It detects any pedestrians, vehicles, and objects in your path and sends warning signals to alert you of their presence. This way, you avoid colliding with any of them. Ignoring the system prompts it to automatically apply the brakes. 

What Does Pre-collision Assist Not Available Sensor Blocked Mean?

The pre-collision assist system is very handy any time you are driving. This explains why an error message such as ‘pre-collision assist not available sensor blocked’ can be alarming. If you understand what the error message may mean will give you the upper hand is solving the issue. 

The pre-collision assist not available sensor blocked is basically a sensor warning that indicates blocked or faulty sensors. If the sensors are blocked, there is no way the system will work.

Hence, the driver receives this error message. It is advisable to address the messages as soon as it displays on the screen. The consequence of ignoring the error message could be severe injury as a result of vehicle collisions. 

What Causes the Pre-collision Assist Sensor to Be Blocked?

Any time this error message pops up, it indicates an issue with the sensor. Hence, it is advisable to troubleshoot the issue as soon as possible. You can do so by identifying the cause. There are different factors at play here besides a blocked sensor. 

For one, the message could pop up due to a dirty sensor. Also, when there is low visibility due to severe weather conditions, you will receive a notification. It could also be attributed to water intrusion on the attached sensor.

If there is ice or snow covers on the front camera and radar, the sensor will not work. Moreover, the severe impact of fog, rain, or spray can keep the system from working. 

How to Solve a Blocked Sensor?

It is easier to resolve the issue once you find out the cause. Still, there are some effective measures to follow. 

For starters, always check the sensors and clean them thoroughly. You can try disconnecting and reconnecting the battery if it is an electrical issue. Also, clean the grill surface in front of the radar sensor.

Always ensure that the front camera and radar are clean and free from snow and ice. Any object that may be obstructing the field of view should be removed. Taking your vehicle for a check and servicing by authorized dealers can also do the trick. 


How does the pre-collision assist system work?

With knowledge of what this system does, it is important to understand how it does it. This system depends on a front camera and an invisible laser. With these two, it can measure the distance between your vehicle and the obstacle. By using information such as your current speed, it can predict if a collision is possible. If so, it will notify you with a signal. The driver is required to slow down upon receiving the alert. Otherwise, the system will automatically apply the brakes. 

What are some of the essential warmings about the pre-collision assist system? 

Inasmuch as the pre-collision system is installed in your vehicle, there are some warnings you need to note. For example, this system is not designed to detect animals. It also does not operate during hard acceleration or steering. The system is unable to detect vehicles that are traveling in different directions. Moreover, it tends to be affected by direct sunlight and severe weather conditions. 


The pre-collision assist system in your vehicle is designed to detect surrounding objects in your path and alert you to slow down or stop where necessary. If the sensor is blocked, you will not receive the alert.

Hence, the system is programmed to send a warning message that the sensor is blocked. Therefore, it is important to identify the root cause of the issue and address it immediately. This will spare you collisions on the road.