What Are Automatic Collision Notification System and How it Works?

    ANCEL x7 advanced car scanner

    Modern ACN systems are often part of a broader suite of telematics services, which might include features like stolen vehicle tracking, roadside assistance, and remote diagnostics.

    By integrating these services, manufacturers aim to enhance overall vehicle safety and security, providing peace of mind to drivers and their families.

    ANCEL has the reliable OBD2 scanner for every vehicle type

    What Are Automatic Collision Notification System and How it Works?

    What Is Automatic Collision Notification

    Automatic Collision Notification (ACN) is an advanced vehicle safety system designed to provide immediate assistance in the event of a severe collision.

    This system, integrated into modern vehicles, automatically alerts emergency services when a crash is detected, ensuring a rapid response that can be crucial for the survival and recovery of those involved.

    ACN employs a combination of sensors, telematics, and communication technologies to determine the severity of a collision and relay vital information to emergency responders.

    When a significant collision occurs, the vehicle's ACN system activates, sending a detailed alert to a central monitoring station or directly to emergency services.

    This alert typically includes the vehicle's exact location, the direction of travel, and the number of occupants.

    The system can provide data on the impact force and whether airbags were deployed, offering emergency personnel critical insights into the potential injuries sustained by passengers.

    The primary goal of ACN is to reduce response times in emergencies, improving the chances of survival and reducing the severity of injuries.

    In rural or less-populated areas where accidents might go unnoticed for extended periods, ACN can be particularly lifesaving.

    Moreover, the system can alleviate the stress on drivers and passengers who might be too injured or disoriented to call for help themselves.

    Related Reading: Why Is My Check Engine Light Flashing?

    What Triggers An Automatic Collision Notification

    Impact sensors located throughout the vehicle play a critical role. These sensors detect sudden deceleration or unusual force, which indicates a collision.

    When the system registers an impact beyond a predetermined threshold, it activates the ACN.

    When airbags are deployed, it generally signifies a severe impact, prompting the system to send out an alert.

    The deployment itself is detected by sensors in the airbag control unit, which immediately communicate with the ACN system.

    Advanced ACN systems may also incorporate gyroscopes and accelerometers to detect rollovers or side impacts.

    These sensors measure the vehicle's orientation and movement in real-time, identifying abnormal patterns that suggest a crash.

    A vehicle tipping beyond a certain angle or experiencing rapid sideways movement might trigger an ACN alert.

    Some systems can be manually activated by occupants.

    If passengers or the driver feel threatened or witness a severe accident, they can press an emergency button within the vehicle to initiate the ACN.

    This manual activation provides an additional layer of safety, ensuring that help can be summoned even if the automated system fails to recognize the collision.

    ANCEL 6 Pro is a powerful diagnostic tool that can detect ABS and SRS issues.

    ABS helps maintain steering control during an emergency braking situation, reducing the risk of collision.

    SRS includes airbags and seatbelt pre-tensioners, which are directly linked to the deployment mechanisms that trigger ACN alerts.

    Car Scanner | ANCEL
    ANCEL V6 PRO+ Bluetooth Bidirectional Scan Tool Full System Car Diagnostic Tool Key Programmer

    Why Is My Collision Warning Light On

    The collision warning light is part of the Forward Collision Warning (FCW) system, designed to alert drivers of an impending collision with a vehicle or object ahead. 

    One common reason is sensor obstruction or malfunction. The FCW system relies on radar, cameras, and other sensors to monitor the road ahead.

    Dirt, snow, or other debris can obstruct these sensors, causing the system to misinterpret the data and trigger a warning.

    Regular cleaning and maintenance of the vehicle's exterior, especially around the sensors, can often resolve this issue.

    Another reason could be software issues.

    The FCW system is controlled by complex software that interprets data from various sensors.

    If the software encounters an error or if there is a glitch, it might trigger the collision warning light. In such cases, a system reset or software update might be required to rectify the problem.

    The warning light might also indicate a genuine risk of collision.

    If you are driving too closely to the vehicle in front or if another vehicle cuts you off suddenly, the FCW system will activate the warning light to prompt you to take immediate action.

    It's crucial to heed these warnings and adjust your driving behavior accordingly to avoid potential accidents.

    In some instances, calibration issues could be the culprit.

    The sensors and cameras in the FCW system need to be precisely calibrated to function correctly.

    Any misalignment due to recent repairs, windshield replacements, or other modifications can affect the system's accuracy, causing the warning light to activate.

    Internal faults within the FCW system itself can cause the warning light to turn on. These faults could be due to wiring issues, defective components, or other mechanical problems that require professional diagnosis and repair.

    If your collision warning light comes on, it's advisable to seek assistance from a qualified mechanic to ensure your safety systems are functioning correctly.

    How Do You Reset a Collision Mitigation Braking System

    Resetting a Collision Mitigation Braking System (CMBS) can be necessary after repairs or if the system malfunctions.

    The CMBS is a critical safety feature designed to prevent or reduce the severity of collisions by automatically applying the brakes when a potential collision is detected. 

    Ensure that your vehicle is parked on a level surface with the engine turned off. Locate the CMBS control unit, usually found within the vehicle's onboard diagnostics system.

    Refer to your vehicle’s manual for the exact location and any specific instructions.

    Turn the ignition to the 'On' position without starting the engine.

    This step allows you to access the vehicle's electronic systems without engaging the engine.

    Find the CMBS button, which is often integrated into the dashboard or near the steering wheel.

    Press and hold this button for several seconds, typically between 10 to 15 seconds, until the CMBS indicator light turns off. This action resets the system.

    In some models, the reset process might require accessing the vehicle’s diagnostic menu through the infotainment system.

    Navigate to the settings menu, select the safety features section, and follow the prompts to reset the CMBS. Consult your vehicle’s manual for detailed instructions specific to your model.

    After resetting the system, turn off the ignition and then restart the vehicle. Observe the dashboard indicators to ensure the CMBS warning light is no longer illuminated.

    If the light persists, there may be an underlying issue that requires professional inspection.

    Resetting the CMBS can often resolve minor issues, but if problems persist, it’s essential to seek professional assistance to ensure the system functions correctly, maintaining the safety of you and your passengers on the road.


    ANCEL also offers a diverse selection of diagnostic tools for heavy trucks, motorcycles, and various other vehicles. These scanners are designed to meet the specific needs of different vehicle types. ANCEL provides reliable and precise auto scan tools that enhance safety and performance. 

    Recommended Similar Articles:

    How to Reprogram a Car Chip Determining Acceptable Mileage for Purchasing a Used Car


    Leave a comment

    Your email address will not be published. Required fields are marked *