Basic Automotive Electrical Diagnostics Practice Test: Prep, Practice Exam & Study Guide

A thermistor is a type of resistor whose resistance varies significantly with temperature. In automotive circuits, thermistors are commonly used in temperature sensing applications. As the temperature changes, the resistance of the thermistor changes in a predictable manner, allowing it to be used for precise temperature measurements. This property makes thermistors essential components in various systems, such as engine management, where they monitor coolant or ambient air temperature to help optimize fuel delivery and engine performance.

The ability of a thermistor to change its resistance based on temperature variations enables it to serve effectively in feedback loops used by the vehicle's electronic control unit (ECU) to adjust various parameters and ensure the engine operates within the optimal range.