What Do Sensors Do in a Vehicle?

What Are Sensors?

From onboard computers to sensors, vehicles have become increasingly advanced over the years. Whether it’s a safety feature like automatic braking or ensuring the engine runs efficiently, sensors are part of the critical technology found in today’s vehicles. Sensors are electronic devices that monitor the various systems and components of the vehicle and send information to the car’s brain, the Electronic Control Unit (ECU). Depending on the situation, the ECU may use the information to make changes to an engine component or could take immediate action like automatic emergency braking.

Sensors and Vehicle Safety

Sensors have played an important role in making vehicles safer. For example, the Electronic Stability Control (ESC) system uses the data that the steering angle sensor gathers to help the driver maintain control during sudden moves or while traveling on slippery surfaces. In addition, Advanced Driver Assistance Systems (ADAS) features like blind-spot monitoring and lane-keep assist uses the information from the steering angle sensor to run these important functions. In the case of anti-lock brakes (ABS), wheel speed sensors monitor the speed of each wheel. If any of the wheels stop turning while the car is moving, the ABS is engaged to help the driver avoid a skid. 

Sensors and Engine Performance

Ensuring optimal engine performance is another key function of sensors. From oxygen sensors to mass air flow sensors, multiple sensors work together to ensure the right amount of fuel is delivered to the engine and that the ignition timing is correct for easy starting. The sensors work in real time to assess the engine performance and make adjustments to the air-fuel ratio and other settings. This instant feedback helps ensure that the vehicle operates properly and in a fuel-efficient manner. 

What Are the Different Sensors in a Vehicle?

From the moment you start up your vehicle, there are dozens of sensors that are constantly working to ensure optimal performance. An average vehicle built in the last 10 years has between 60-100 sensors and the number increases each year.

Listed below are some of the sensors that can be found on many vehicles. Please note that this is not an exhaustive list and that your vehicle may not include all these sensors.

Engine:

Designed to optimize the performance of the engine and reduce emissions, engine sensors monitor the pressure, temperature, fuel injection, air flow and other aspects of the engine. Some common engine sensors include:

Oxygen Sensor

Measures amount of oxygen in the exhaust; data is used to adjust the air-fuel ratio to reduce emissions and improve fuel efficiency. Also known as an O2 sensor.

Mass Air Flow (MAF) Sensor 

Measures the amount of air entering the engine; information is used to adjust the fuel injection to prevent engine stalling.

Coolant Temperature Sensor 

Monitors the engine coolant temperature; information is used to operate the cooling fan or take other measures to keep the engine at the optimal temperature. It also helps provide the correct amount of fuel to the engine. Cold engines require more fuel to start than warm engines.

Knock Sensor 

Looks for unintended vibration and sounds coming from the engine block; information is used to possibly alter the ignition timing.

Position Sensors

Position sensors measure the angles and positions of various parts throughout the vehicle with high accuracy. Using the information, the vehicle’s computer can react to changes and determine the next action. Common position sensors include:

Camshaft Position Sensor

Monitors rotation of the camshaft; data is used to coordinate the opening and closing of the intake and exhaust valves during ignition.

Crankshaft Position Sensor

Detects the speed and position of crankshaft; information is used to control the fuel injection and ignition timing.

Wheel Speed Sensor

Monitors the speed of each wheel; information is used to operate the ABS, traction control and stability control systems.

Steering Angle Sensor

Tracks position of the steering wheel; information is used with lane departure warning, stability control, ABS and automatic emergency braking.

Safety Sensors

From deploying air bags to detecting objects in the way, safety sensors are crucial to ensuring that the driver and passengers arrive safely to their destination. These sensors are key in ADAS systems like park assist and blind spot detection.

Air Bag Sensor

Detects an impact and upon determining the severity of the collision, it deploys the air bags.

Tire Pressure Monitoring System (TPMS)

Monitors the pressure in the tires and alerts the driver if the pressure in any of the tires are at an unsafe level.

Parking Sensors

Sensors in front and rear bumpers detect objects that are close and alerts driver with beeps and graphics on the dashboard display.

Blind Spot Detection

Using a camera or radar, this sensor sends a warning to the driver when a vehicle or object is in a driver’s blind spot to ensure safe merging or lane changing.

Learn more about quality sensors, find your car part, or find where to buy your auto part today.

The content in this article is for informational purposes only. You should consult with a certified technician or mechanic if you have questions relating to any of the topics covered herein. Tenneco will not be liable for any loss or damage caused by your reliance on any content.