The Coolant Temperature Sensor (CTS) is a thermistor type sensor that has a variable resistance when exposed to different temperatures. The CTS senses coolant temperature. See Figure 3-8.
The ECM uses the CTS signal to determine the quantity and timing of fuel required to optimize starting over a range of temperatures (only Series 4000 engines).
The CTS provides a signal to vary idle speed and injection timing resulting in improved cold starts and reduced white smoke. It also activates the engine protection if the oil temperature exceeds the specified limits (only Series 4000 engines).
See Figure 3-9 for the CTS used in the Series 2000 and Series 4000 engine construction and industrial applications, and Intercooler Coolant Temperature Sensor (ICTS) used in the Series 4000 engine construction and industrial applications.
