Page 776 - Foton Workshop Manual - Auman EST-M

EG - 260 Engine section – Engine (Cummins ISF3.8)

Coolant temperature sensor
Overview
1. Coolant temperature sensor is used to measure the engine coolant temperature, convert engine
coolant temperature to an electrical signal and transmit to the ECM, so that the ECM determines the
engine operating conditions in order to control the fuel injection.

2. The coolant temperature sensor controls the coolant temperature through the negative temperature
coefficient thermistor. Temperature higher, resistance smaller. This resistance is a part of bleeder circuit
which is applied with 5V voltage Measure the voltage on the resistance changing according to the
temperature. Each voltage corresponds with a temperature on the ECM internal characteristic curve
Performance parameters and technical specifications

Type Technical specifications

Maximum measurement current 5mA

Nominal resistance at 20 ℃ 2.5kΩ

Working temperature -30~130℃
Work response time About 15s

-40℃ Corresponding resistance (45.313±9.7) kΩ

-30℃ Corresponding resistance (26.114±8.8)kΩ

-10℃ Corresponding resistance (9.397±7.1) kΩ
0℃ Corresponding resistance (5.896±6.4) kΩ

10℃ Corresponding resistance (3.792±5.0) kΩ

Resistance temperature 30℃ Corresponding resistance (1.707±5.7) kΩ
characteristics
50℃ Corresponding resistance (0.8339±6.7) kΩ

70℃ Corresponding resistance (0.4357±7.7) kΩ
90℃ Corresponding resistance (0.2432±8.6) kΩ

110℃ Corresponding resistance (0.1442±9.3) kΩ

130℃ Corresponding resistance (0.0712±10.3) kΩ

140℃ Corresponding resistance (0.0712±10.3) kΩ

EG-260