Hyundai Sonata: Engine Coolant Temperature Sensor (ECTS). Description and Operation
Description
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 that changes resistance with the temperature.
The electrical resistance of the ECTS decreases as the temperature increases,
and increases as the temperature decreases. The reference +5V is supplied to
the ECTS via a resistor in the ECM. That is, the resistor in the ECM 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 ECM increases the fuel injection duration
and controls the ignition timing using the information of engine coolant temperature
to avoid engine stalling and improve drivability.

Intake Air Temperature Sensor (IATS). Repair procedures
Inspection
1.
Turn the ignition switch OFF.
2.
Disconnect the IATS connector.
3.
Measure resistance between th ...
Engine Coolant Temperature Sensor (ECTS). Specifications
Specification
Temperature
Resistance (kΩ)
°C
°F
-40
-40
48.14
-20
-4
...
See also:
Dimensions
*1 : with R16 tire
*2 : with R17 tire
*3 : with R18 tire ...
Description and Operation
Warning Lamp Activation
Warning Lamp Behavior after Ignition
On
As soon as the operating voltage is applied to the SRSCM ignition input,
the SRSCM activates the warning lamp fo ...
Limitation of Active ECO operation
If the following conditions occur while Active ECO is operating, the system operation
is limited even though there is no change in the ECO indicator.
When the coolant temperature is low: The sys ...
