Diagnosis And Testing - Radiator Fan Control: Notes

WARNING: This page is about a different car, the 2004 Dodge Intrepid, 2004 Chrysler Intrepid, 2004 Chrysler Concorde, and 2004 Chrysler 300M. However, it is still accessible from the selected car via links, so may be relevant.

Radiator fan control can be accomplished five ways. A pressure transducer on the air conditioning compressor discharge line sends a signal to the Powertrain Control Module (PCM) which will activate both fans if necessary. In addition to this control, the fans are turned on based on coolant temperature sensor, intake air temperature sensor, output speed sensor, and transmission oil temperature sensor output to the PCM. The PCM switches the fans on through the fan relays.

The PCM provides fan control for the following conditions:

Regardless of coolant temperature the fan will not run during cranking until the engine starts;
Fans will run in accordance with the specifications listed in the following operation charts.
For additional circuit and diagnostic information (Refer to Appropriate Wiring and Diagnostic Information).