Circuit Description

Cooling fan motor is controlled by PCM through cooling fan relay. PCM uses Engine Coolant Temperature (ECT) sensor output to calculate when to operate engine cooling fan motor. When engine temperature is greater than 208°F (98°C), PCM will provide a ground path for cooling fan relay and activate cooling fan motor. When engine temperature drops to less than 199°F (93°C), PCM will remove ground path and deactivate cooling fan motor. DTC P0480 will set when low voltage is indicated at cooling fan relay control terminal for 5 seconds with engine coolant temperature less than 199°F (93°C).

When DTC sets, MIL will illuminate after 2 consecutive ignition cycles in which diagnostic runs with active fault. PCM will record operating conditions at time of failure and store information in freeze frame buffer.