Monitor Description
WARNING: This page is about a different car, the 2025 Lexus RX 350, 2024 Lexus RX 350, and 2023 Lexus RX 350. However, it is still accessible from the selected car via links, so may be relevant.
6, 6.5 and 7 hours after the engine has stopped, the ECM monitors the voltage of the ECM internal temperature sensor and intake air temperature sensor.
If the difference between the readings of the ECM internal temperature and intake air temperature is more than 20°C (36°F), the ECM determines that there is a malfunction in the ECM internal temperature sensor circuit or intake air temperature sensor circuit and stores a DTC and illuminates the MIL.