Thermostat Monitor

OBD System Description - Thermostat Monitor

System Description / Monitoring Procedure
The engine block temperature is estimated to modelize accumulated combustion heat value since engine start (based on mass intake air flow) and radiation heat value (radiation from engine, radiation when fuel shutoff, etc.). The heat exchange value between engine and engine coolant is estimated, and the engine coolant temperature is estimated. When estimated temperature reaches the specified temperature and the measured temperature is lower than criteria, the malfunction is detected.

DTC Description / Detecting Condition / Confirmation Procedure

P0128
Refer to DTC P0128: Coolant Thermostat. P0128

Operation:

Enable Condition:

Typical Malfunction Thresholds:

Thermostat Monitor Operation