Monitor Description
WARNING: This page is about a different car, the 2024 Lexus IS 500, 2023 Lexus IS 500, and 2022 Lexus IS 500. However, it is still accessible from the selected car via links, so may be relevant.
The ECM monitors the idle speed and idling air flow volume to conduct idle speed control. The ECM determines that the idle speed control system is malfunctioning if either of the following conditions is met:
- The difference between the target engine idle speed and actual engine idle speed exceeds the threshold and the IAC flow rate learned value is stuck at the upper or lower limit for 5 seconds or more.
- After driving at a vehicle speed of 10 km/h (6.25 mph) or more, the difference between the target and actual engine idle speed exceeds the threshold 5 times or more during a driving cycle, and then the system determines that the IAC flow rate learned value is stuck at the upper or lower limit, or that the IAC flow rate learned value has been changed by an amount that exceeds the threshold.