Idle Relearn Procedure: Description
WARNING: This page is about a different car, the 2003 Saturn Vue. However, it is still accessible from the selected car via links, so may be relevant.
The engine control learns the idle position of the throttle body for correct operation. When the throttle body or ECM is replaced, this procedure must be performed to ensure correct idle operation. The engine idle may be unstable or a DTC may set if the idle position has not been learned.