Where is the collision sensor located?

In most passenger cars, collision sensors are located in the front corners and along the sides of the vehicle, with additional sensors near the lower dash. Exact placement varies by model.

Modern safety systems rely on multiple sensors to detect crashes quickly and deploy airbags, so locations can differ between manufacturers and between frontal, side, and pedestrian protection strategies.

Typical Automotive Collision Sensor Placements

The following list outlines common mounting points used in passenger cars to detect crashes from different directions.

• Front crash sensors: usually mounted behind the front bumper or in the front crash rails, near the left and right corners, to detect frontal impacts early.


• Side crash sensors: installed in the door pillars (A- or B-pillar) or within the door panels to sense lateral impacts; some systems also use seat-mounted sensors for enhanced side protection.


• Central or multi-axis accelerometers: in some designs, a center crash sensor or centralized accelerometer located near the vehicle’s center of gravity helps synchronize deployment across airbags.


• Supplementary occupant-side sensing: seat-based or knee-area sensors that help determine occupant size/weight and refine airbag timing (part of the restraint system, not a primary crash sensor by itself).

These placements are chosen to cover different crash directions, enable rapid data for the airbag control unit, and provide redundancy across a vehicle’s safety network.

Non-Automotive Collision Sensing – other contexts

Collision sensing isn’t limited to cars. In robotics, aviation, drones, and consumer electronics, sensors are placed according to the device’s geometry and operating environment. Here are common mounting choices in non-automotive systems:

• Robotics and industrial automation: front-facing sensors on robotic arms or chassis, bumper switches, and distributed sensors along the frame to detect contact or proximity.


• Drones and unmanned vehicles: obstacle-avoidance sensors mounted around the nose or frame perimeters, sometimes with downward-facing units for ground detection.


• Smartphones and wearables: accelerometers and gyroscopes integrated near the device’s core to detect sudden motion, orientation changes, or impacts, without exposed external housings.

In all cases, placement aims to balance detection speed, reliability, and avoidance of false alarms, tailored to each system’s safety and operational requirements.

Why Placement Matters

Where sensors sit determines how quickly and accurately a system can respond to a collision or obstacle. Front and side sensors are designed to detect different impact directions, while centralized sensors support coordinated responses and redundancy.

Summary: Collision sensor location is context-specific. In cars, expect front and side sensors near bumper edges and pillars; in other devices, sensors are positioned to maximize coverage and minimize false triggers. Understanding these placements helps explain how safety and avoidance systems function in real-world use.

Why is my collision warning light on?

Your collision warning light is on because the system is either detecting an immediate hazard, the sensors are blocked, or there is a malfunction. Common causes for the light to be on include obstructions on the windshield or front sensors, adverse weather conditions like heavy rain or snow, and driving through areas with strong radar reflections like hills or tunnels. A persistent light may indicate a need for a system reset, a more serious electrical issue, or that the system has been turned off.
 
You can watch this video to learn how to reset the collision warning light: 57sDashboard warning lights YouTube · Sep 4, 2025
Common reasons for the light to be on

• Blocked sensors: The most frequent reason is a blockage on the front of your car. This could be dirt, snow, ice, or even bugs on the windshield, or on the radar/camera sensors themselves. 
• Adverse weather: Heavy rain, fog, or snow can interfere with the system's ability to see clearly, causing it to shut off or trigger a warning. 
• Environmental factors: Driving through tunnels, under bridges, or in areas with a lot of metal objects (like construction zones or guardrails) can cause the sensors to get confused and trigger false alarms. 
• Driver behavior: If you are following too closely or braking suddenly, the system may interpret this as a potential collision and warn you. 
• System malfunction: The light could indicate a fault in the system itself, which may require a professional inspection. 

What you can do

• Inspect and clean the sensors: First, check your windshield and front-facing sensors for any dirt, snow, or ice and clean them thoroughly. 
• Change your driving habits: If the light comes on frequently in normal driving conditions, you may need to increase the distance you leave between yourself and the car in front of you. 
• Adjust sensitivity: Your car may have a setting to adjust the sensitivity of the collision warning system. Check your vehicle's settings to see if this is an option. 
• Perform a system reset: A simple hard reset, such as disconnecting the car battery for a while, might clear any temporary glitches. If this doesn't work, there could be a more serious issue. 
• Consult your owner's manual or a professional: If the light remains on after you've tried these steps, consult your vehicle's owner's manual for specific troubleshooting information or contact a qualified mechanic.

This video demonstrates how to troubleshoot the collision warning system: 57sDashboard warning lights YouTube · Aug 27, 2025

What does a crash sensor look like?

So here's an overview of how the airbag. System works the airbag sensor senses a deceleration. During a collision. And will send a signal to the SRS.

How to reset front collision sensor?

System this could be labeled with a car icon. And some lines in front of it. All you need to do is press and hold that button for a few seconds.

Where is the collision warning sensor located?

Crash sensor locations vary by vehicle but are commonly found on or behind the front bumper, on the upper radiator support, or beneath the fenders on the driver and passenger sides. Some older vehicles may have a single sensor, while newer cars often have multiple sensors located in these front-end areas, sometimes requiring the bumper to be removed for access.
 
You can watch this video to see the location of the crash sensors on a car: 44sAuto Repair GuysYouTube · Feb 4, 2021
Common locations

• Radiator support: Sensors are often mounted on the upper radiator support or the frame/crash bar behind the radiator. 
• Under the front bumper: Many vehicles have sensors positioned directly behind the front bumper, sometimes requiring it to be removed to access. 
• Under the fenders: Some models, particularly BMWs, place the sensors under the fenders in the front corners of the vehicle. 
• Frame rails: In some cases, sensors can be found on the inner or outer sides of the frame rails. 

How to identify them

• Connectors: Crash sensors are often identifiable by their yellow connectors, as yellow is a standard color for airbag system components. 
• Number: While some older cars may have one sensor, modern vehicles typically have at least two, often one on the driver's side and another on the passenger's side.