ECT Sensor: The scan tool displays -40°C to +151°C
(-40°F to +304°F). The Engine Coolant Temperature (ECT) sensor
is mounted in the coolant stream. The PCM 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 the PCM monitors a high signal voltage
and interprets it as a cold engine. As the sensor warms the voltage
signal decreases and the PCM interprets the lower voltage
as a warm engine.
FC Relay 1 Command: The scan tool displays On or Off.
The PCM is commanding Fan Control relay 1 On when the scan tool indicates
On. When the PCM commands the Fan Control relay 1 On,
both fans are enabled on low speed.
FC Relay 2 and 3 Command: The scan tool displays On
or Off. The PCM is commanding all 3 fan control relays on when the scan
tool indicates On. When all fan control relays are activated,
both cooling fans are enabled on high speed.
FC Relay 1 Circuit Status: The scan tool displays OK
, Fault, or Invalid State. This parameter indicates the state of the driver
circuit for this device.
FC Relay 2 and 3 Circuit Status: The scan tool displays
OK , Fault, or Invalid State. This parameter indicates the state of the
driver circuit for this device.