Monitor Description
WARNING: This page is about a different car, the 2006 Lexus RX 400h. However, it is still accessible from the selected car via links, so may be relevant.
The ECM (Included in HV Control ECU) monitors the idling speed and idling air flow volume to conduct Idle Speed Control (ISC). The ECM determines that the ISC system is malfunctioning if the following conditions apply:
- The learned idling air flow volume remains at the maximum or minimum 5 times or more during a drive cycle
- While driving at 6 mph (10 km/h) or more, the actual engine idling speed varies from the target idling speed by between 100 RPM and 200 RPM, 5 times or more during a drive cycle.
Example:
If the actual idling speed varies from the target idling speed by more than 200 RPM* 5 times during a drive cycle, the ECM illuminates the MIL and sets the DTC.
HINT:
*: Threshold idling speed varies with engine load.