P0484: Fan Circuit Current High

P0484 monitors the current drawn in the fan's load circuit: if it exceeds a threshold – blocked or stiff motor, shorted turns, a short in the load circuit – the code sets. This is only possible where the fan runs on a current-measuring semiconductor driver or fan module; plain relay circuits do not measure load current. Supplier patents (Bosch and others) describe current limiting or switch-off after a few seconds of overcurrent, ignoring the inrush current. No manufacturer table available to us lists P0484, so thresholds and warning-lamp behaviour remain open; CARB requires output components to be monitored.

Medium severity. Can I keep driving?Watch the temperature gauge. If it climbs or a warning appears, stop the car in a safe place and turn off the engine: overheating can cause serious damage.

Symptoms

Warning lamp (depending on the maker)
Fan does not run, runs only briefly or at reduced power
Humming or grinding at the fan, possibly blown fan fuse
Overheating at standstill

Most likely causes

Fan motor stiff (bearing damage) or blocked (foreign object, ice, bent blade)
Shorted turns or worn brushes in the fan motor
Short in the load circuit (pinched or chafed wire)
Fan control module faulty (wrong current measurement)

What to check, in order

Start with the simplest. You can tick off each step.

With the engine cold, check the coolant level; never do this when the system is hot
Check the sensor's ground and make sure the signal wire is not receiving voltage from another circuit.
Check the actual temperature in live data
Make sure the fan comes on when it should
Check the thermostat and connector
Measure the sensor and replace it if its readings do not make sense

Good to know

Repair difficulty: medium
It affects emissions.

What each character of P0484 means

P: Powertrain: engine and transmission
0: Generic code: same on every make
4: Emissions
84: Specific fault in that system

Frequently asked questions

Can I keep driving with code P0484?

Watch the temperature gauge. If it climbs or a warning appears, stop the car in a safe place and turn off the engine: overheating can cause serious damage.

What causes code P0484?

The most common causes are: fan motor stiff (bearing damage) or blocked (foreign object, ice, bent blade); shorted turns or worn brushes in the fan motor; short in the load circuit (pinched or chafed wire).

Related codes

Sources

Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.