OBD Codes

P0483

Cooling Fan Rationality Check Malfunction

Moderatecooling

Overview

The P0483 diagnostic trouble code indicates a cooling fan rationality check malfunction condition. This code relates to the engine cooling system, which maintains proper operating temperature for the engine. Cooling system problems can lead to overheating and serious engine damage if not addressed in a timely manner.

Symptoms

  • Coolant leak
  • Engine overheating
  • Poor heater performance
  • Check Engine Light (MIL) illuminated

Common Causes

  • Faulty thermostat (stuck open or closed)
  • Low coolant level or coolant leak
  • Failed water pump
  • Damaged radiator hoses

Diagnosis Steps

  1. 1Connect an OBD-II scanner and read all stored trouble codes and freeze frame data
  2. 2Check coolant level and inspect for visible leaks
  3. 3Test the thermostat by monitoring coolant temperature during warm-up
  4. 4Inspect the coolant temperature sensor and its wiring
  5. 5Test the cooling fan operation by running the AC or using a scan tool

Estimated Repair Cost

$100$800

Cost varies by vehicle, location, and repair shop. Includes parts and labor.

Commonly Affected Vehicles

Nissan MuranoBMW 3 SeriesChevrolet CruzeJeep Grand Cherokee

Related Codes

More Cooling Codes

Frequently Asked Questions

If your engine is overheating, stop driving immediately to prevent catastrophic engine damage. If the code is related to a sensor or thermostat and the temperature is stable, drive cautiously to a repair shop.