This Preliminary Information communication provides information to the technician on the step to diagnose and repair the vehicles that may have a shake or shudder during light throttle acceleration, between 30 and 65 mph steady state driving. Also shudder feeling that may be described as driving over rumble strips or rough pavement. Technician will drive the vehicle and monitor the torque converter clutch slip. The torque converter clutch slip speed should be 10 rpm or less also note if the shudder takes place during torque converter clutch apply. If the torque converter clutch slip speed is in the range of 10 RPM or less the condition is possibly related to engine performance. If the shudder is only present in 4 cylinder mode and torque converter clutch slip is 10 rpm or less deem the shudder concern normal characteristic of Active Fuel Management. If the slip speed is beyond 10 rpm or there is shudder during torque converter clutch apply the torque converter will need to be replaced with a updated part number.