GM Service Manual Online
For 1990-2009 cars only

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.

Perform the following procedure in order to allow the ECM to learn the idle position:

  1. Ensure that the following conditions are met:
  2. • The vehicle speed is 0 mph.
    • The accelerator pedal angle is less than 14.9 percent.
    • The battery voltage is more than 10 volts.
    • The engine coolant temperature (ECT) is between 5-100°C (41-212°F).
    • The intake air temperature (IAT) is more than 5°C (41°F).
  3. Turn OFF the ignition for 30 seconds.
  4. Turn ON the ignition, with the engine OFF for 60 seconds.
  5. Turn OFF the ignition.