General Information

Component Location





General Description

An Engine Coolant Temperature Sensor (ECTS) monitors the temperature of the coolant. This input is used by the ECM for engine control and as an enabling criteria for related diagnostics. The air flow coming into the engine is accumulated and used to determine if the engine has been driven within conditions that would allow the engine coolant to heat up normally to the thermostat regulating temperature. If the coolant temperature does not reach regulating temperature of the thermostat, diagnostics that use engine coolant temperature as enabling criteria, may not run when expected.
This DTC will set when there has been excessive time to reach a minimum coolant temperature required for closed loop fuel control.

DTC Description

An open stuck thermostat means an increase of the engine warm up time and can cause emission increase as well. To detect open stuck thermostat, the ECM checks measured coolant temperature as soon as calculated coolant temperature reaches threshold and sets DTC P0128 when measured coolant temperature is lower than threshold. If same code is set again in the next driving cycle, MIL is illuminated.

DTC Detecting Condition





Specification

[ECTS]





[THERMOSTAT]






Schematic Diagram





Signal Waveform