Scan Tool Data Definitions

Scan Tool Data Definitions

Commanded Fan 1/Commanded Fan 2: Scan tool displays ON or OFF. Represents the powertrain control module (PCM) commanded state of the fan 1 (low speed) and fan 2 (high speed) control circuits.
Coolant Hot Lamp: The scan tool displays ON/OFF. The scan tool displays ON when the engine coolant is above 151°C (260°F).
Coolant Temperature: The scan tool displays 40°C to 151°C (-40°F to 304°F). This data is the coolant temperature the Instrument Cluster is attempting to display on the coolant temperature gauge.
ECT: The scan tool displays -40°C to 151°C (-40°F to 304°F). The Engine Coolant Temperature (ECT) sensor is mounted in the coolant stream. The 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. FC Relay 1: The scan tool displays OK or Fault. This parameter indicates the state of the driver circuit for this device.
FC Relay 2 and 3: The scan tool displays OK or Fault. This parameter indicates the state of the driver circuit for this device.