FUNCTION AND OPERATION PRINCIPLE
Engine Coolant
Temperature Sensor (ECTS) is located in the engine coolant passage of the
cylinder head for detecting the engine coolant temperature. The ECTS uses
a thermistor whose resistance changes with the temperature. The electrical
resistance of the ECTS decreases as the temperature increases, and
increases as the temperature decreases. The reference 5 V in the PCM is
supplied to the ECTS via a resistor in the PCM.That is, the resistor in
the PCM and the thermistor in the ECTS are connected in series. When the
resistance value of the thermistor in the ECTS changes according to the
engine coolant temperature, the output voltage also changes. During cold
engine operation the PCM increases the fuel injection duration and
controls the ignition timing using the information of engine coolant
temperature to avoid engine stalling and improve drivability.
SPECIFICATION
Temperature
|
Resistance(kΩ)
|
°C
|
°F
|
-40
|
-40
|
48.14
|
-20
|
-4
|
14.13 ~
16.83
|
0
|
32
|
5.79
|
20
|
68
|
2.31 ~
2.59
|
40
|
104
|
1.15
|
60
|
140
|
0.59
|
80
|
176
|
0.32
|
SCHEMATIC DIAGRAM
COMPONENT INSPECTION
| 1. |
Turn ignition switch
OFF. |
| 2. |
Disconnect ECTS
connector. |
| 4. |
After immersing the thermistor of the sensor
into engine coolant, measure resistance between ECTS terminals 1 and
3. |
| 5. |
Check that the resistance is within the
specification.
Specification: Refer to
SPECIFICATION.
| |
