Which component is an example of a sensor in automotive systems?

• A. Fuel injector
• B. MAP sensor
• C. Throttle body
• D. Ignition coil

Answer: (B)

Understanding which automotive component acts as a sensor hinges on recognizing that a sensor measures a physical property and reports it to the engine control unit. The MAP sensor fits this role because it measures the pressure inside the intake manifold (manifold absolute pressure) and converts that pressure into an electrical signal that the ECU uses to estimate air density and determine how much fuel to inject and how to time the ignition. This sensing role is what makes it a sensor.

The other items aren’t sensors. A fuel injector is an actuator that delivers fuel. The throttle body is the air intake control device (it may house position sensors, but the throttle body itself is not a sensor). An ignition coil is an actuator that generates the high voltage needed to create a spark.