Scan Tool Data Definitions

Scan Tool Data Definitions

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) or engine control module (ECM) 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 or ECM monitors a high signal voltage and interprets it as a cold engine. As the sensor warms and internal resistance decreases, the voltage signal decreases and the PCM or ECM interprets the lower voltage as a warm engine.

FC Relay 1 Circuit Status

This parameter indicates the status for the state of the driver circuit.

FC Relay 1 Command

The scan tool displays On or Off. This parameter indicates the commanded state of the low speed fan relay driver.

FC Relay 2 and 3 Circuit Status

This parameter indicates the status for the state of the driver circuit.

FC Relay 2 and 3 Command

The scan tool displays On or Off. This parameter indicates the commanded state of the high speed fan relay driver.