Coolant Temperature: The scan tool displays -40
to +151°C (-40 to +304°F). This data is the coolant temperature the
Instrument Cluster is attempting to display on the coolant temperature gage.
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 powertrain control module (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, internal resistance high, the PCM 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 interprets the lower voltage
as a warm engine.
Cooling Fan Speed Command: The scan tool displays %. This parameter
indicates the commanded state of the cooling fan.
Coolant Level Input: The scan tool displays OK or Low. If the
ground circuit opens, the scan too will display Low.