OBD-II Code
P0485
Severity
Not yet reviewed
Nobody on our side has assessed this code yet, so we are not going to guess at how serious it is.
Can you drive it
We cannot say
Treat it as unknown until a shop reads it with live data. If the check-engine light is FLASHING, stop driving as soon as it is safe to — that means an active misfire, whatever the code.
Indicative cost (USD)
$80–$1,200
From this code's diagnostic notes. Varies by vehicle, diagnosis, parts, and local labor. This is not a repair quote.
$80 (corroded connector + dielectric grease) to $1,200 (TIPM replacement on a Caravan or Grand Cherokee).
P0485 is a cooling-fan power or ground circuit malfunction — the ECM/BCM detected an electrical fault on the fan's primary power feed, ground return, or both.
How a shop works this
Work from evidence to part, not the other way round. A code names a circuit or a symptom; it does not name the part that failed.
Note every code that is set, not just this one.
Codes that appear together usually narrow the cause faster than any one of them read alone.
Read the freeze frame — the conditions the fault was recorded under.
Cold or warm, idle or load, road speed and engine speed. A fault that only appears cold is a different fault from one that only appears under load, even with the same code on the scanner.
Confirm the fault is current rather than history.
Clear the code and see whether it returns under those same conditions. A code that does not come back may have been logged during a repair, a flat battery, or a bad connection that has since been disturbed.
Then follow the diagnostic notes further down this page, in the order they are written.
They are written in the order a shop works this code, cheapest checks first. Where they name a component, inspect its wiring and connector before replacing it.
If the code comes back after a repair, the underlying fault is still there. That is the point to bring in a scanner with live data and freeze-frame, or a shop that has one.
Common symptoms
- Check engine light
Read the full diagnostic procedureP0485 is a cooling-fan power or ground circuit malfunction — the ECM/BCM detected an electrical fault on the fan's primary power feed, ground return,…
P0485 is a cooling-fan power or ground circuit malfunction — the ECM/BCM detected an electrical fault on the fan's primary power feed, ground return, or both.
This differs from P0484 (rationality) in that P0485 specifies a measured circuit problem
open, short to power, short to ground, or excessive resistance. Cheapest-first ladder: pull the fan connector at the shroud, key-on engine-off, and measure voltage at the power-feed pin with a DMM (should be 12-14V battery voltage when commanded on, less than 0.5V when commanded off). Then ground-side: measure voltage drop from the fan ground pin to the battery negative post under load — anything above 0.3V indicates corrosion, a broken strap, or a chassis ground point with paint behind it. Then clamp-meter the current draw during a commanded fan-on cycle: 3-8A at low speed, 15-30A at high speed; less than 1A means an open circuit (broken wire, blown maxi-fuse, or open motor winding), more than 35A sustained means a binding bearing or shorted winding pulling the fan toward fuse-popping current. Inspect the fan blades and shroud for debris (mouse nests, leaves jammed between blade and shroud are surprisingly common). Expensive-misdiagnosis caveat: on platforms where the fan share a fused power feed with other cooling system loads (water pump on hybrid setups, AC condenser fan), a short in any one component pops the same fuse and sets P0485 — verify the fault is actually at the fan motor before replacing it, because pulling a transmission cooler line or a shorted AC wire can repeatedly destroy fan motors when current spikes route through them.
Vehicle-specific patterns1997-2014 Ford F-150 with the PWM electric fan throws P0485 when the heavy-gauge power feed from the under-hood relay/MaxiFuse box corrodes at the fi…
- 1997-2014Ford F-150 with the PWM electric fan throws P0485 when the heavy-gauge power feed from the under-hood relay/MaxiFuse box corrodes at the firewall pass-through or at the FCM connector — the high inrush current burns connector terminals over time.
- 2007-2014GM 1500/2500 trucks (Silverado, Sierra, Tahoe, Yukon, Suburban) throws P0485 when the dual-fan power harness chafes against the radiator support and shorts to ground; GM issued TSBs on harness routing.
- 2008-2016Dodge Grand Caravan / Chrysler Town & Country throws P0485 from the well-documented TIPM (Totally Integrated Power Module) fan relay failure — the internal relay solders crack and the relay either welds closed (fan runs constantly, kills battery) or fails open (overheat).
- 2011-2017Jeep Grand Cherokee with the 3.6L Pentastar V6 throws P0485 from the same TIPM relay failures.
- 2010-2015Toyota Prius (and other hybrid models) throws P0485 from inverter cooling fan failures that share fuses with the main radiator fan circuit.
Estimated repair$80 (corroded connector + dielectric grease) to $1,200 (TIPM replacement on a Caravan or Grand Cherokee).
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