Trouble codes › P0125
P0125 Insufficient Coolant Temperature for Closed Loop Fuel Control
Cooling
P0125 means the engine took too long to warm up enough for normal fuel control, usually a thermostat stuck open.
The engine computer waits for the coolant to warm up before it starts fine-tuning fuel using the oxygen sensors. P0125 means the engine took too long to get warm enough, usually because the thermostat is stuck open.
Safe to drive. Expect weak cabin heat in cold weather and worse fuel economy until it's fixed.
Common causes
- A thermostat stuck open (most common)
- Low coolant level
- A failing coolant temperature sensor
- A cooling fan running all the time
Symptoms
- Temperature gauge slow to rise or reading low
- Weak heater
- Poor fuel economy
What to check first
- Check the coolant level when cold.
- Watch the coolant temperature warm up on a drive: it should reach normal in about 10-15 minutes.
- Check that the fans aren't running on a cold engine.
- Replace the thermostat (and sensor if it reads wrong).
What does P0125 mean on your vehicle?
The likely cause depends on your engine. iRepair researches your exact year, make, model and engine (service bulletins, recalls and owner reports) and tells you what to check first. Your first 3 questions are free.
Ask iRepair about P0125No scanner? Most auto parts stores read check-engine codes for free.
Related codes
General guidance for P0125 on most vehicles. Some makers use the same code a little differently; confirm in the service information for your vehicle, put safety first, and see a professional when in doubt.