Scan Tool Data Definitions

Scan Tool Data Definitions
AC Clutch: The parameter indicates On whenever the Powertrain Control Module (PCM) energizes the A/C compressor clutch relay. Engaging the A/C compressor clutch relay will also engage the cooling fan at low speed.

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 to +140°C, (-40 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 Powertrain Control Module (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.