This Preliminary Information communication provides information to the technician about vehicles that may have harsh 1-2 shift, mostly on light throttle with no Diagnostic Trouble Codes present. If the concern is duplicated it is possible the trans shift adaptive time may not have learned. Technician should drive the vehicle in M5 with the cruise control set to a speed above 38 miles per hour and drive for about 5 miles on level ground. Second drive audit may be needed, if yes, allow the Transmission Electro-Hydraulic Control Module to power down prior to the second attempt. If no change after the drive audit, follow Service Information diagnoses for a harsh shift concern.
