DTC P0480: Cooling Fan Control Relay No. 1 Circuit: Description

WARNING: This page is about a different car, the 2002 Saturn LW200, 2002 Saturn L200, and 2002 Saturn L100. However, it is still accessible from the selected car via links, so may be relevant.

PCM controls both cooling fan motors by controlling 2 drivers, which pull fan control circuits to ground. Combination of high/low inputs to cooling fan control module allow off, low, medium and high cooling fan speeds. When PCM fan control driver is off, cooling fan control module input is high (battery voltage). When PCM fan control driver is on, cooling fan control module input is low (zero volts). Both cooling fan motors will begin to run whenever ECT is more than 210°F (99°C), A/C is commanded on with high side pressure more than 174 psi (1199 kPa) or a low/high fault exists in ECT sensor circuit. DTC sets when fan control No. 1 is being commanded off and feedback voltage at PCM is low, or when fan control No. 1 is being commanded on, and feedback voltage at PCM is high.