本页暂无Chinese版本，以下为英文原文。 查看英文版 →
P0125 P0xxx · 动力总成（P） 低严重度
Insufficient Coolant Temperature for Closed Loop Fuel Control
The engine has been running long enough that it should be in closed-loop fuel control, but the ECU never sees the coolant reach the expected temperature. Almost always a thermostat that is stuck open.
严重程度说明： 低——通常不影响行驶，下次保养时处理即可
你会注意到的故障现象
- Heater blows lukewarm
- Temperature gauge below normal
- Higher fuel consumption
- Emissions test failure
常见原因
按可能性从高到低排列——从最上面开始查。
- 1 Thermostat stuck open
- 2 Failed coolant temperature sensor reading low
- 3 Very cold ambient use with a short journey cycle
如何排查
先做花钱最少、侵入最小的检查——大多数这类码不是零件问题。
- ✓ Watch ECT on a scan tool during a 10-minute drive; it should stabilise around 85–95 °C.
- ✓ Feel the upper and lower radiator hoses — both getting warm early means the thermostat is open.
- ✓ Compare ECT with a infrared thermometer on the housing.
维修方案
- Replace the thermostat
- Replace the ECT sensor if it reads implausibly low
- Bleed the cooling system
P0125 —— 常见问题
Is this urgent? +
Not mechanically urgent, but running rich long-term damages the catalytic converter and washes oil films off cylinder walls.
Could it just be a cold day? +
In sub-zero conditions with short trips, yes — confirm with a longer drive before replacing parts.