Fault code: P0128
Chinese meaning: Coolant thermostat (coolant temperature is lower than the thermostat adjustment temperature)
English meaning: Coolant Thermostat (Coolant Temperature Below Thermostat Regulating Temperature)
Category:
Fuel or Air
The function of the thermostat is to close when the coolant temperature is low and only allow The coolant circulates in the engine to increase the speed of heating the car; when the water temperature exceeds the set temperature, the thermostat opens to circulate the coolant to the water tank radiator, effectively improving cooling efficiency. The fault code indicates that the thermostat did not reach the required engine operating temperature within a set amount of time after the engine was started. Causes include a thermostat stuck in the open position and a faulty engine coolant temperature (ECT) sensor.