Which device sends information to the vehicle’s control module?

• A. Sensor
• B. Actuator
• C. Relay
• D. Switch

Answer: (A)

Signals from sensors feed the control module with data about the vehicle’s state. A sensor converts a physical parameter—such as temperature, pressure, position, or speed—into an electrical signal that the module can read and use to make decisions. The control module relies on this information to regulate systems and respond appropriately. An actuator, on the other hand, is driven by the module to perform a task, like moving a component. A relay switches power to a circuit under the module’s control; it doesn’t provide input data. A switch can supply a simple on/off input, but it doesn’t measure a parameter in the same way a sensor does. Therefore, the device that sends information to the vehicle’s control module is the sensor.