P0480: How to Diagnose & Fix — Cooling Fan 1 Control Circuit

Various plastic coolant flanges and fittings can crack and leak, particularly on the side of the engine. These plastic components become brittle with age and heat exposure. Multiple leak points possible.

The electric cooling fan module on the Grand Wagoneer has been documented to fail, causing the dual electric radiator fans to run at reduced speed or stop entirely, resulting in engine coolant temperature spikes especially at low speeds and in traffic. The fan control module can develop internal MOSFET failures due to heat cycling, and Stellantis issued related service guidance through their dealer network. Owners report the temperature gauge rising into the red zone during stop-and-go driving and the A/C compressor cutting out as a secondary symptom.

The 3.6L Pentastar JK uses a single electric radiator fan driven by a pulse-width-modulated (PWM) duty-cycle signal from the TIPM rather than a simple on/off relay. The integrated fan motor/controller fails, or the PWM signal circuit faults, so the fan won't spin up at speed — causing overheating in traffic and on trails and setting P0480 (Cooling Fan 1 Control Circuit). Because the fan is commanded by the TIPM through a 3-wire design, the fault can lie in the fan module, the signal wire, grounds (G102 near the passenger headlight), or the TIPM itself, which makes it tricky to diagnose. Overheating risks head/gasket damage on a Pentastar.

The single electric cooling fan module used on the ProMaster City fails in two ways: the fan control relay/circuit drops out, and the plastic fan blade separates or the motor seizes. Owners report the fan literally melting off its motor. Because the 2.4L relies entirely on this one fan at low road speed, failure shows up first in stop-and-go delivery duty as a temperature gauge climbing at idle that recovers on the highway. CarComplaints ranks cooling-fan-relay malfunction with engine overheating as the worst reported defect on the 2015 model year, with reports around 24,000-25,000 miles and repair costs near $600-650. A ProMaster City owner documented the dealer replacing the relay for a P0481 code, only to have the van overheat again about 100 miles later because the fan motor itself was the failed part. The same fan module family is used on the Jeep Renegade. Note this is a separate defect from the full-size Ram ProMaster 3.0L diesel / 3.6L gas cooling fan seizure recall - that recall does not cover the City.

The mechanical (belt-driven) water pump on HEMI-powered Challengers is a recurring weak point that can fail well before normal service life, with owners reporting failures across a very wide mileage band — some as early as ~5,800-7,000 miles, clusters around 18,000-25,000 miles, and others out past 45,000-60,000 miles. The OEM Mopar pump uses a plastic impeller pressed onto a sealed bearing-and-shaft assembly. The dominant failure mode is bearing wear: as the bearing develops play and roughness, the shaft seal weeps coolant (a telltale trail of dried/crusty glycol residue on the pump body, distinct from harmless minor weep-hole staining), and in worse cases the loose impeller rubs the inside of the timing-cover/block bore, shearing plastic vanes off the impeller. Shed plastic circulates into the cooling system while the now-degraded impeller stops moving coolant effectively, producing localized overheating that can escalate to engine damage. This is a distinct component and failure set from the separately documented OEM radiator cooling issue — same system, different part. Dodge's own DodgeGarage how-to acknowledges the inspection points (loose/rough bearing and seal-deposit trail), and many owners and some dealers treat it as a known HEMI weak spot. A common, well-regarded fix is replacing the OEM plastic-impeller pump with a metal-impeller aftermarket unit (e.g., Gates) rather than another identical OEM pump.