GM Service Manual Online
For 1990-2009 cars only

Idle Learn Procedure

Anytime the PCM or the battery is disconnected, the PCM looses power, or the PCM is reprogrammed, the PCM's learned idle position is lost. The engine idle is unstable when the learned idle position is lost.

Perform the following procedure in order to return the learned idle to the correct position:

Automatic Transmission

  1. Turn OFF the ignition.
  2. Restore the PCM battery feed.
  3. Turn OFF the A/C controls.
  4. Set the parking brake and block the drive wheels.
  5. Start the engine.
  6. Allow the engine coolant temperature to reach 80°C (176°F)
  7. Shift the transmission selector into the drive range.
  8. Allow the engine to idle for 5 minutes.
  9. Turn ON the A/C controls.
  10. Allow the engine to idle for 5 minutes.
  11. Shift the transmission selector into the park range.
  12. Allow the engine to idle for 5 minutes.
  13. Turn OFF the A/C controls.
  14. Allow the engine to idle for 5 minutes.
  15. Turn OFF the engine for 30 seconds.

Manual Transmission

  1. Turn OFF the ignition.
  2. Restore the PCM battery feed.
  3. Turn OFF the A/C controls.
  4. Set the parking brake and block the drive wheels.
  5. Transmission in neutral.
  6. Start the engine.
  7. Allow the engine coolant temperature to reach 80°C (176°F)
  8. Turn ON the A/C controls.
  9. Allow the engine to idle for 5 minutes.
  10. Turn OFF the A/C controls.
  11. Allow the engine to idle for 5 minutes.
  12. Turn OFF the engine for 30 seconds.