Monitor Description
WARNING: This page is about a different car, the 2006 Toyota Land Cruiser. However, it is still accessible from the selected car via links, so may be relevant.
The ECM detects idle speed and idle air flow amount for Idle Speed Control (ISC). The ECM concludes that the ISC is malfunctioning if: 1) the learned value of the ISC remains at the maximum or minimum 5 times or more during a drive cycle, and 2) while driving at 10 km/h (6 mph) or more, the actual idle RPM varies from the target RPM by between 100 to 200 RPM 5 times or more during a drive cycle.
Example:
If the actual idle RPM varies from the target idle RPM by more than 200 rpm* 5 times during a drive cycle, the ECM will turn on the MIL and a DTC is set.
HINT:
*: RPM threshold varies with engine load.