Temperature sensors monitor the thermal state of various vehicle systems, most commonly engine coolant, intake air, oil, and exhaust gases. These sensors utilize thermistors—semiconductors whose resistance changes predictably with temperature—to provide voltage signals to the Engine Control Unit (ECU). The ECU interprets these signals to adjust fuel delivery, ignition timing, and cooling fan operation for optimal performance and emissions control. Sensor housings are constructed of materials compatible with the monitored fluid/gas and operating temperatures, and electrical connectors are sealed for environmental protection. Modern designs increasingly incorporate digital signal processing for improved accuracy and communication via protocols like CAN.