A coolant temperature sensor (CTS) is a device used to measure the temperature of the coolant in an internal combustion engine. It is typically located in the engine block or cylinder head, and its job is to send a signal to the engine’s electronic control unit (ECU) indicating the current coolant temperature. The ECU uses this information to adjust the engine’s timing, fuel mixture, and other parameters to ensure optimal performance and fuel efficiency.
A faulty CTS can lead to a number of problems, including: