Radiator Cooling Fan Control Module: Testing and Inspection

Fan control is accomplished two ways. The fan always runs when the air conditioning compressor clutch is engaged. In addition to this control, the fan is turned on by the temperature of the coolant, which is sensed by the coolant temperature sensor which sends the message to the Powertrain Control Module (PCM). The (PCM) turns on the fan through the Solid State Fan Relay. The Solid State Fan Relay is located on the left front inner frame just behind the radiator. See Electrical Diagrams for circuity and diagnostics provided.
Switching through the (PCM) provides fan control for the following conditions.
^ The fan will not run during cranking until the engine starts no matter what the coolant temperature is.
^ Fan will run when the air conditioning clutch is engaged and low pressure cutout switch is closed.
^ Fan will run at vehicle speeds above about 40 mph only if coolant temperature reaches 110° C (230° F). It will turn off when the temperature drops to 104° C (220° F). At speeds below 40 mph the fan switches on at 102° C (215° F) and off at 93° C (200° F).

For additional diagnostic information, please refer to the procedures at Powertrain Management. Testing and Inspection