2015 GMC Sierra HD

GM: INFORMATION INVOLVING THE PROCEDURE TO ENSURE THAT FUSE BLOCK IS PROPERLY RETAINED. THE RETENTION CLIPS THAT ATTACH THE FUSE BLOCK TO THE BODY MAY LOOSEN PERMITTING THE FUSE BLOCK TO MOVE OUT OF POSITION. *JS

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 miles per hour steady state driving. Also shudder feeling that may be described as driving over rumble strips or rough pavement. Technician will need to run the vehicle in three different operational modes. The three modes are Normal, torque converter clutch open, and torque converter clutch closed. Technician will need to press and hold the tow-haul mode button for five seconds to disable grade braking to prevent downshifts during test. Technician will need to duplicate the concern in Normal mode. If the concern is gone in torque converter clutch open and closed then the torque converter should be replaced. If the concern is not present in normal mode, torque converter clutch open, and torque converter clutch closed the concern is not with the shudder. Technician should use of the PICO scope and Noise, Vibration and Harshness software can be used to confirm torque converter clutch shudder, Engine, Tire or Driveline component related conditions. Flush the cooler lines and cooler using DT-45096 transmission oil cooling system flush and flow test tool when the torque converter is replace.

This Preliminary Information communication advises the technician how determine if the vehicle is equipped with wireless fidelity. Technician should check the Regular Production Option Code list for (VV4).