Download To improve the transmission shift feeling during specific operating modes, the Engine Control Module (ECM) (SAE term: Powertrain Control Module/PCM) calibration has been revised. These improvements include: S Reduced downshift lag when accelerating at speeds from 10 to 20 mph. S Less gear hunting when driving on/off accelerator pedal at 20 to 30 mph (for example: during heavy rush–hour traffic). S Improved response rate during heavy acceleration from a stop. NOTE: S Version 12.2a or later Diagnostic Tester software is required to perform this procedure. S Before proceeding, verify the ECM (PCM) calibration has NOT been updated by checking for the Authorized Modifications Label (shown in step 1 of the Repair Procedure). S Harsh ATM shifting may result if any Repair Procedure steps are omitted (specifically steps 5 and 11 on page 6). Repair Procedure 1. Check for the Authorized Modifications Label affixed to the vehicle in the location shown in Figure 1.