Two kinds of cooling fan carry these codes: electric fans switched by relays or driven by a PWM/LIN fan module with speed feedback, and engine-driven fans with an electronically controlled viscous clutch, whose speed a Hall sensor reports – GM calls them EV fans, meaning electro-viscous, not electric vehicle. P0483 checks the fan's function, not its circuit. With a speed sensor (GM viscous fans) commanded and actual speed are compared: GM's Duramax diesels of 2014–18 set it at more than ±500 rpm for at least 120 s, GM petrol SUVs and pick-ups of 2004–06 at more than 1000 rpm – MIL after two trips. Without a sensor Subaru (and the Saab 9-2X) judges indirectly: if coolant at 100 °C or more does not fall within 5 minutes at idle with the fan on, the code sets after two trips. Ford's OBD summaries do not contain it.
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
- Check engine light on (after two trips)
- Constant fan roar, or temperature rise at standstill
- Air conditioning weak at low speed
Most likely causes
- Viscous clutch worn or leaking, or its solenoid faulty – fan does not reach or leave target speed
- Electric fan motor stiff or worn, or fan blocked
- Fan speed sensor or wiring giving a wrong value
- Radiator or condenser clogged, coolant low (Subaru logic)
- Drive belt slipping (belt-driven viscous fan)
What to check, in order
Start with the simplest. You can tick off each step.
Good to know
- Repair difficulty: medium
- It affects emissions.
What each character of P0483 means
- P: Powertrain: engine and transmission
- 0: Generic code: same on every make
- 4: Emissions
- 83: Specific fault in that system
Frequently asked questions
Can I keep driving with code P0483?
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 P0483?
The most common causes are: viscous clutch worn or leaking, or its solenoid faulty – fan does not reach or leave target speed; electric fan motor stiff or worn, or fan blocked; fan speed sensor or wiring giving a wrong value.
Related codes
- P0526Fan Speed Sensor Circuit
- P0527Fan Speed Sensor Circuit Range/Performance
- P0495Fan 1 Overspeed
- P0494Fan 1 Underspeed
- P0480Fan 1 Control Circuit
- P0128Coolant Thermostat (Coolant Temperature Below Thermostat Regulating Temperature)
Sources
- gsi.ext.gm.com: 18OBDG04 Engine Diagnostics
- gsi.ext.gm.com: 14OBDG10 Engine Diagnostics
- gsi.ext.gm.com: 2005file2
- static.nhtsa.gov: SB 10052205 7383
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.