LEMON Manuals: Even more car manuals for everyone
Home >> Lexus >> 2007 >> SC 430 >> Repair and Diagnosis >> Engine Performance >> Testing & Diagnosis >> Engine Control System >> SFI System >> DTC P0115 Engine Coolant Temperature Circuit; DTC P0117 Engine Coolant Temperature Circuit Low Input; DTC P0118 Engine Coolant Temperature Circuit High Input >> Monitor Description

Monitor Description

The ECT sensor is used to monitor the engine coolant temperature. The ECT sensor has a thermistor that varies its resistance according to the temperature of the engine coolant. When the coolant temperature is low, the resistance in the thermistor increases. When the temperature is high, the resistance drops. The variations in resistance are reflected in the output voltage from the sensor. The ECM monitors the sensor voltage and uses this value to calculate the ECT. When the sensor output voltage deviates from the normal operating range, the ECM interprets this as a fault in the ECT sensor and sets a DTC.

Example:

When the ECM calculates that the ECT is -40°C (-40°F) (P0118) or more than 140°C (284°F) (P0117) and that either condition continues for 0.5 seconds or more, the ECM will set a DTC. This monitor runs for 0.5 seconds after the ignition switch is turned ON.

scientia non olet · About LEMON Manuals