For 1990-2009 cars

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.

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.
Fan Control 1 Command: This parameter displays the control module commanded state of the cooling fan low relay.
Fan Control 2 Command : This parameter displays the control module commanded state of the cooling fan high relay.
Fan Control 3 Command : This parameter displays the control module commanded state of the cooling fan control relay.
Fan Low: This parameter displays the control module commanded state of the cooling fan low relay.
Fan High: This parameter displays the control module commanded state of the cooling fan relays that are required to enable high speed fan operation. When this parameter is indicating ON, all three cooling fan relays should be energized.