Scan Tool Data Definitions

Scan Tool Data Definitions
Battery Voltage 1
The scan tool displays 0-12 volts of battery voltage at the BCM.

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 signal circuit. The sensor is a thermistor which changes internal resistance as temperature changes. When the sensor is cold and the internal resistance is high, the PCM monitors a high signal voltage and interprets it as a cold engine. As the sensor warms and the internal resistance decreases, the voltage signal decreases and the PCM interprets the lower voltage as a warm engine.

FC Relay 1, FC Relay 2 Command
The scan tool displays On or Off. This parameter indicates the state of the driver circuit for this device.