DTC Description

DTC DETECTION LOGIC

Engine coolant temperature has not risen enough to open the thermostat even though the engine has run long enough.

This is due to a leak in the seal or the thermostat being stuck open.

DTC	CONSULT screen terms (Trouble diagnosis content)	DTC detection condition
P0128	THERMSTAT FNCTN [Coolant thermostat (coolant temperature below thermostat regulating temperature)]	Diagnosis condition	-
		Signal (terminal)	Engine coolant temperature sensor signal
		Threshold	The engine coolant temperature does not reach to specified temperature even though the engine has run long enough.
		Diagnosis delay time	-

POSSIBLE CAUSE

FAIL-SAFE

Not applicable