Scan Tool Data Definitions

AC Relay Command:  This parameter indicates the commanded state of the A/C clutch control (MG) relay. The A/C clutch should be engaged when the scan tool displays on.

AC Request Signal:  This parameter indicates whether the A/C switch on the instrument panel (IP) has been selected.

ECT Sensor:  The scan tool range is -40°C to +140°C (-40°F to +284°F). The engine coolant temperature (ECT) sensor is a thermistor which changes internal resistance as the temperature changes. When the sensor is cold (internal resistance high), the PCM monitors a high signal voltage and interprets the voltage 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.