Scan Tool Data Definitions 3.8L

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.

Engine Hot Lamp: The scan tool displays On or Off. This parameter indicates the state of the indicator lamp.

Engine Hot Lamp Circuit Status: The scan tool displays OK or Fault. This parameter indicates the state of the driver circuit for this device.

Engine Hot Lamp Command: The scan tool displays On or Off. This parameter indicates the state of the indicator lamp.

Fans High Speed: The scan tool displays On or Off. The PCM is commanding all three fan control relays on when the scan tool indicates On. When all fan control relays are activated, both cooling fans are enabled on high speed.

Fans Low Speed: The scan tool displays On or Off. The PCM is commanding Fan Control relay 1 On when the scan tool indicates On. When the PCM commands the Fan Control relay 1 On, both fans are enabled on low speed.

FC Relay 1: The scan tool displays OK or Fault. This parameter indicates the state of the driver circuit for this device.

FC Relay 1 Circuit Status: The scan tool displays OK or Fault. This parameter indicates the state of the driver circuit for this device.

FC Relay 1 Command: The scan tool displays On or Off. This parameter indicates the state of the low speed fan relay driver.

FC Relay 2 and 3: The scan tool displays OK or Fault. This parameter indicates the state of the driver circuit for this device.

FC Relay 2 and 3 Circuit Status: The scan tool displays OK or Fault. This parameter indicates the state of the driver circuit for this device.

FC Relay 2 and 3 Command: The scan tool displays On or Off. This parameter indicates the state of the high speed fan relay driver.

Scan Tool Data Definitions 3.6L

The Scan Tool Data Definitions list contains a brief description of all of the cooling system related parameters that are available on the scan tool. The list is arranged in alphabetical order. A given parameter may appear in any one of the data lists. In some cases the parameter may appear more than once, or in more than one data list in order to group certain related parameters together.

Calculated ECT - Thermostat Diagnosis: This parameter displays the modeled temperature that the control module calculates from air entering the engine, coolant temperature, and ambient air temperature. If the actual engine coolant temperature does not reach this calculated temperature within a predetermined amount of time, a DTC will set.

ECT Sensor: This parameter displays the temperature of the engine coolant based on input to the control module from the engine coolant temperature (ECT) sensor.

FC Relay 1 Circuit Status:  This parameter displays the state of the fan relay control circuit. The parameter displays Indeterminate when no circuit fault is detected when the fans are OFF. The parameter displays OK when no circuit fault is detected when the fans are ON.

FC Relay 1 Command: This parameter displays the control module commanded state of the fan relay control circuit.

FC Relay 2 and 3 Circuit Status:  This parameter displays the state of the fan relay control circuit. The parameter displays Fault if the fan relay control circuit is open, shorted to ground, or shorted to voltage. The parameter displays Indeterminate when no circuit fault is detected when the fans are OFF. The parameter displays OK when no circuit fault is detected when the fans are ON.

FC Relay 2 and 3 Command: This parameter displays the control module commanded state of the fan relay control circuit.