Possible causes

– Low engine coolant level
– Leaking or stuck open thermostat
– Faulty Engine Coolant Temperature (ECT) sensor
– Engine Coolant Temperature (ECT) sensor harness is open or shorted
– Engine Coolant Temperature (ECT) sensor electrical circuit poor connection

When is the code detected?

The voltage sent to Engine Control Module (ECM) from the Engine Coolant Temperature (ECT) sensor is not practical, even when some time has passed after starting the engine. The engine is taking too long to reach the normal temperature level.

Symptoms

– Engine Light ON (or Service Engine Soon Warning Light)

P0125 Description

The Engine Coolant Temperature (ECT) sensor is used to detect the engine coolant temperature. The sensor modifies a voltage signal from the Engine Control Module (ECM). The modified signal returns to the ECM as the engine coolant temperature input. The sensor uses a thermistor which is sensitive to the change in temperature. The electrical resistance of the thermistor decreases as temperature increases.

P0125 Information for specific makes

P0125 HYUNDAI
P0125 NISSAN
P0125 INFINITI
P0125 ACURA
P0125 HONDA
P0125 CHRYSLER
P0125 JEEP
P0125 DODGE
P0125 FORD
P0125 KIA
P0125 LEXUS
P0125 TOYOTA
P0125 SCION
P0125 MITSUBISHI
P0125 SUBARU
P0125 MAZDA
P0125 VOLKSWAGEN
P0125 AUDI
P0125 JAGUAR
P0125 BUICK
P0125 CADILLAC
P0125 CHEVROLET
P0125 GMC
P0125 PONTIAC
P0125 SATURN