The ECM 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 volume 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 150 rpm, 5 times or more during a drive cycle.
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.
: Threshold idling speed varies with engine load.
Was this article helpful?