P0125
Insufficient Coolant Temperature for Closed Loop Fuel Control
Moderatecooling
Overview
The P0125 diagnostic trouble code indicates a insufficient coolant temperature for closed loop fuel control 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
- Temperature gauge reading high
- Engine overheating
- Coolant leak
- Poor heater performance
Common Causes
- Malfunctioning cooling fan or relay
- Faulty engine coolant temperature sensor
- Air in the cooling system
- Failed radiator cap
Diagnosis Steps
- 1Connect an OBD-II scanner and read all stored trouble codes and freeze frame data
- 2Check coolant level and inspect for visible leaks
- 3Test the thermostat by monitoring coolant temperature during warm-up
- 4Inspect the coolant temperature sensor and its wiring
- 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
Mercedes-Benz C-ClassChevrolet CruzeNissan MuranoBMW 3 Series
Related Codes
More Cooling Codes
P0115Engine Coolant Temperature Circuit Malfunction
ModerateP0116Engine Coolant Temperature Circuit Range/Performance
ModerateP0117Engine Coolant Temperature Circuit Low Input
ModerateP0118Engine Coolant Temperature Circuit High Input
ModerateP0119Engine Coolant Temperature Circuit Intermittent
ModerateP0126Insufficient Coolant Temperature for Stable Operation
ModerateFrequently 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.