Computer Command Control - Throttle Body Fuel Injection

The ECM controls the engine coolant fan relay under several operating conditions. If the coolant temperature sensor indicates high engine temperature, the ECM will energize the relay to turn "ON" the fan. If the A/C is engaged, the ECM will turn the coolant fan on to cool the condenser as well as the radiator. Some fault codes will cause the ECM to turn on the fan. Above certain vehicle speeds, the ECM will de-energize the fan relay since at higher road speeds there is ample air flow.