Idle Speed & Mixture Adjustments: Notes

NOTE: Idle mixture is controlled by Single Board Engine Controller (SBEC). No adjustment is possible.

Electronically fuel injected vehicles use an Automatic Idle Speed (AIS) motor or Idle Speed Control (ISC) actuator to regulate idle RPM. The AIS or ISC is controlled by the SBEC, which uses information received from various sensors to determine, among other things, idle speed. Curb idle speed is not adjustable. See the appropriate G - TESTS W/ CODES article in this section for diagnosis of incorrect idle speed.