If vehicle battery was disconnected or Powertrain Control Module (PCM) was replaced, driving the vehicle will enable the PCM to perform a computer relearn procedure for obtaining proper drivability and engine idle. Until PCM has completed computer relearn procedure, drivability or idle may differ from standard vehicle operation. On A/T models, transaxle shift qualities must be relearned. And for more GM vehicles projects,check here:GM vehicle repair cases
Procedures
1On all models, start engine and warm engine to normal operating temperature. Perform 10 sets of upshifts (1-2, 2-3 and 3-4) at about 30 percent throttle.
2On DOHC engine, while coasting at 35 MPH, slowly accelerate to 1/2 throttle to achieve a 4-3 downshift. Place gearshift in “D3” while coasting at 20 MPH, slowly accelerate at 3/4 throttle to achieve a 3-2 downshift.
3Repeat step 2) five times. Vehicle drivability computer relearn procedure is now complete.
4On SOHC engine, while coasting at 40 MPH, slowly accelerate to 1/2 throttle to achieve a 4-3 downshift. Place gearshift in “D3” while coasting at 30 MPH, slowly accelerate at 1/2 throttle to achieve a 3-2 downshift.
5Repeat step 4) five times. Vehicle drivability computer relearn procedure is now complete.