General Information
Component Location
General Description
The 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 5V 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.
DTC Description
The Engine Coolant Temperature High Rationality Diagnostic checks for unusually high engine coolant temperatures under normal operating loads.
PCM monitors difference between the startup and current coolant temperature and compares against the threshold while enable condition is met. If the PCM detects that the coolant temperature exceeds the limit under normal operating condition, PCM determines that a fault exists and a DTC is stored.
DTC Detecting Condition
Specification
Schematic Diagram
Signal Waveform