Case CX130B Crawler Excavator Service Manual

Table of Contents

1. General Information
2. Engine
3. Fuel System
4. Electrical System
5. Undercarriage
6. Drive Train
7. Upper structure Hydraulics
8. Hydraulic Schematics
9. Electrical Schematics

Manual Extract: Coolant temperature sensor

The coolant temperature sensor is installed on the engine block, and the thermistor changes the resistance in accordance with the temperature. Resistance is low when the
engine coolant temperature is high and high when engine coolant temperature is low. The engine control module (ECM) applies 5 V to the coolant temperature sensor through pull-up resistance, calculates the engine coolant temperature from the voltage change, and this is used in various types of control such as fuel injection control. Voltage is low if the resistance is small (high temperature) and high if the resistance is large (low temperature).