P0494

Fan 1 Underspeed

Moderate severity

Cooling fan 1 is rotating slower than commanded. The ECU sees the tachometer feedback below the expected window for the requested duty cycle - usually a worn fan motor, a high-resistance harness or feed, or a partially seized impeller.

Common causes

Fan 1 motor worn or brushes degraded
One of the most commonly reported causes for this code — check this first.
high
Typical part cost: $130-550
High contact resistance in feed
A plausible cause — test and verify before replacing parts.
medium
Typical part cost: $130-550
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First things to check

1Confirm the code with a scan tool and check for additional related codes.
2Inspect the relevant sensors, wiring, and connectors for damage or corrosion.

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Related codes

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Frequently asked questions

What does P0494 mean?

P0494 means "Fan 1 Underspeed". It is a generic OBD-II code that points to a fault in the auxiliary emission controls.

What are the most common causes of P0494?

fan 1 motor worn or brushes degraded; high contact resistance in feed; fan impeller seized or blocked — these are the most commonly reported causes. Verify with a proper diagnosis before replacing parts, or use the Wrenchify app for a vehicle-specific diagnosis.

Can I keep driving with this code?

The vehicle is usually drivable for short distances, but the problem can worsen or affect emissions. Diagnose and repair as soon as practical. Use the Wrenchify app for a full diagnosis specific to your vehicle.

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