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Home >> Lexus >> 2017 >> IS 300 F Sport >> Repair and Diagnosis >> External Pages >> Different car >> Section 109 (Engine Control System (2UR-GSE) - Diagnostic Codes (1 Of 4)) >> SFI System >> DTC P0128: Thermostat [11/2021 - ] >> Typical Malfunction Thresholds

Typical Malfunction Thresholds

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JUDGMENT BY SIMULATED ENGINE COOLANT TEMPERATURE

Duration that both of the following conditions are met 5 seconds or more
Estimated engine coolant temperature 75°C (167°F) or higher
Engine coolant temperature sensor output Less than 75°C (167°F)
JUDGMENT BY ENGINE COOLANT TEMPERATURE CHANGE AT HIGH VEHICLE SPEED

Malfunction counter 3 times or more
Malfunction counter is incremented when following conditions are met A and B
A. Average engine coolant temperature change (vary with current engine coolant temperature, estimated ambient air temperature, intake air mass and vehicle speed) Less than -0.0439°C/sec (-0.079°F/sec)
B. Engine coolant temperature is satisfied throughout this period Less than 75°C (167°F)