ECT: The scan tool displays -40 to +151°C
(-40 to +304°F). The Engine Coolant Temperature (ECT) sensor
is mounted in the coolant stream. The PCM/ECM applies 5 volts to the ECT
sensor circuit. The sensor is a thermistor which changes internal resistance
as temperature changes. When the sensor is cold (internal resistance
high), the PCM/ECM monitors a high signal voltage and interprets it
as a cold engine. As the sensor warms (internal resistance decreases), the
voltage signal decreases and the PCM/ECM interprets the lower voltage
as a warm engine.
FC Relay 1 Command: The scan tool displays OK or Fault. This
parameter indicates the state of the driver circuit for this device.
FC Relay 2 and 3 Command: The scan tool displays OK or Fault.
This parameter indicates the state of the driver circuit for this device.