Hyundai Sonata: Engine Control System / Engine Coolant Temperature Sensor (ECTS) Description and Operation
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.

Inspection
1.
Connect a GDS on the Data Link Connector (DLC).
2.
Measure the output voltage of the BPS at idle and IG ON.
Specification: Refer to "Specification"
Removal
1.
Turn th ...
Specification
TemperatureResistance (k?)°C°F-40-4048.14-20-414.13 ~ 16.830325.7920682.31 ~ 2.59401041.15601400.59801760.32
...
Other information:
Hyundai Sonata LF 2014-2019 Service Manual: Smart Key Unit Repair procedures
Removal
Smart Key Unit
1.
Disconnect the negative (-) battery terminal.
2.
Remove the glove box.
(Refer to Body - "Glove Box Upper Cover Assembly")
3.
Remove the smart key unit (B) after disconnecting the connectors (A) and loosening the bolt and nut.
Interior 1 Antenna
...
Hyundai Sonata LF 2014-2019 Owners Manual: Hazard Warning Flasher
The hazard warning flasher serves as a warning to other drivers to exercise extreme
caution when approaching, overtaking, or passing your vehicle.
It should be used whenever emergency repairs are being made or when the vehicle
is stopped near the edge of a roadway.
To turn the hazard warning flas ...