Monitor Description
WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2024 Lexus ES 300h, 2023 Lexus ES 300h, 2022 Lexus ES 300h, 2021 Lexus ES 300h, and 2020 Lexus ES 300h. However, it is still accessible from the selected car via links, so may be relevant.
The ECM monitors the difference between the No. 2 engine coolant temperature and the intake air temperature when the engine is started cold to accurately detect the engine temperature conditions. The monitor runs when the engine is started after 7 hours or more have elapsed since the power switch was turned off in the previous trip. If the difference between the engine coolant temperature and the intake air temperature on a cold start exceeds 25°C (45°F), the ECM interprets this as a malfunction in the No. 2 engine coolant temperature sensor circuit or intake air temperature sensor circuit, illuminates the MIL and stores this DTC.