The official notice
Defect
VEHICLE DESCRIPTION: PASSENGER VEHICLES EQUIPPED WITH 4T65E AUTOMATIC TRANSMISSIONS. THESE VEHICLES FAIL TO CONFORM TO THE REQUIREMENTS OF FMVSS NO. 102, "TRANSMISSION SHIFT LEVER SEQUENCE." A RETAINING CLIP, WHICH SECURES THE MANUAL VALVE TO THE LINKAGE OF THE TRANSMISSION DETENT LEVER, CAN BECOME LOOSE UNDER A COMBINATION OF POSSIBLE DRIVER SHIFTING MANEUVERS AND ALLOW THE LINK TO BECOME DISCONNECTED FROM THE MANUAL VALVE.
Safety Risk
IF THE LINK DISCONNECTS, THE DRIVER'S INDICATED PRNDL STATE MAY DIFFER FROM THE HYDRAULIC STATE OF THE TRANSMISSION. IF THE DRIVER SELECTS 'DRIVE' AND THE TRANSMISSION IS ACTUALLY IN 'REVERSE', A VEHICLE CRASH COULD OCCUR.
Remedy
DEALERS WILL REPLACE THE MANUAL VALVE/LINK ASSEMBLY WITH A REPLACEMENT MANUAL VALVE/LINK KIT, FEATURING A SPRING-TYPE FASTENER.