ECT Sensor: 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 powertrain control module (PCM) or engine control module (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 ON or OFF. This parameter indicates the state of the driver circuit for this device.
FC Relay 2 and 3 Command: The scan tool displays ON or OFF. This parameter indicates the state of the driver circuit for this device.
FC Relay 1 Circuit Status: The scan tool displays OK or Fault. This parameter indicates the status for the state of the driver circuit for this device.
FC Relay 2 and 3 Circuit Status: The scan tool displays OK or Fault. This parameter indicates the status for the state of the driver circuit for these devices.
Ignition 1 Signal: The scan tool displays Voltage. This parameter indicates the status of voltage at the PCM/ECM.