이 페이지는 아직 Korean로 제공되지 않습니다. 영어 원문을 표시합니다. 영문으로 보기 →
P0125 P0xxx · 동력계 (P) 심각도 낮음
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.
심각도 안내: 낮음 — 주행성에 영향이 거의 없으며 다음 정비 시 처리하세요
확인할 수 있는 증상
- Heater blows lukewarm
- Temperature gauge below normal
- Higher fuel consumption
- Emissions test failure
주요 원인
가능성이 높은 순서로 정렬되어 있습니다. 위부터 확인하세요.
- 1 Thermostat stuck open
- 2 Failed coolant temperature sensor reading low
- 3 Very cold ambient use with a short journey cycle
점검 방법
비용이 적고 침습적이지 않은 항목부터 — 대부분의 코드는 부품 문제가 아닙니다.
- ✓ 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.
수리 방법
- Replace the thermostat
- Replace the ECT sensor if it reads implausibly low
- Bleed the cooling system
P0125 — 자주 묻는 질문
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.