The engine-mounted cooling fan, also known as the viscous fan, is controlled by the PCM and should be checked by a qualified repair shop if it is not coming on and causing the engine to overheat. Symptoms of fan clutch failure include noisy operation, looseness, vibration, and fluid leakage. To check the fan, rock it back and forth for excessive bearing play and turn the blades by hand. For a hot engine check, start the engine and let it warm up, then turn off the engine and try turning the fan by hand. For a radiator-mounted electric cooling fan, if it is not coming on, the fan motor can be tested by connecting it directly to the battery. For component replacement, the viscous and electric cooling fans are removed together. For diesel engines, the process is similar, but there may be additional steps. For 2010 and later models, the process involves disconnecting the battery, removing the radiator top cover plate, detaching the viscous fan, and unclipping the fan shrouds.

For component replacement, the viscous and electric cooling fans are removed together. The process involves disconnecting the battery, removing the radiator top cover, holding the engine fan pulley while unscrewing the viscous fan mounting nut, removing the fan shroud bolts, disconnecting the wiring, detaching the clips, and lifting the complete assembly out of the vehicle. For diesel engines, the process is similar, but there may be additional steps such as removing the fan shroud and detaching the wiring harness. For radiator-mounted electric fans on 2010 and later models, the process involves disconnecting the battery, removing the radiator top cover plate, detaching the viscous fan, disconnecting the wiring, unbolting the fan shrouds, unclipping them, and pulling the entire assembly out of the vehicle