2000 IMPALA P0480 Fault Code: Fan Circuit Issue Diagnosis and Solutions
What is the common cause of the P0480 fault code in a 2000 IMPALA? The vehicle's cooling fan activates when engine temperature exceeds normal levels, but it turns off prematurely once temperature returns to normal. Additionally, the fan engages immediately when the air conditioning is turned on. The code reappears after clearing. This behavior suggests an issue with the fan circuit control system. Possible root causes include faulty fan relays or a malfunctioning Powertrain Control Module (PCM) that fails to detect proper relay configuration. Please advise if this is a known issue for 2000 IMPALA models and how to diagnose it effectively.
Check the fan relays. The relays control whether the fan circuit operates in series or parallel modes, enabling high or low-speed operation. These relays are commanded by the PCM. If the relay configuration is incorrect or faulty, the PCM may not detect the intended fan behavior, leading to P0480 code activation.