2005 GMC YUKON XL 1500 Power Train Problems

MY 2005 YUKON XL WILL, AT RANDOM, SHIFT ITSELF INTO 4 WHEEL LO. IT HAPPENS WHILE DRIVING AND AT SPEEDS OF 30+ MPH. ALL OF THE LIGHTS ON THE PUSH-BUTTON 4WD CONTROL MODULE WILL LIGHT UP OR FLASH. NO AMOUNT OF BUTTON-PUSHING WILL DISENGAGE 4 WHEEL DRIVE. I THE CAR WILL SLAM TO A 5 MPH CRAWL WHEN IT DOES THIS. ALSO THE TRACTION CONTROL SYSTEM DEACTIVATES AT THE SAME TIME. HAS HAPPENED OVER 40 TIMES NOW.

THIS BASIC INCIDENT HAS OCCURRED APPROXIMATELY TEN TIMES. THE 4WD CONTROL MODULE MALFUNCTIONS AT RANDOM. THE VEHICLE MESSAGE CENTER WILL DISPLAY "SERVICE 4WD," AND A CLICKING SOUND CAN BE HEARD AS THE LIGHTS ON THE TRANSFER CASE CONTROL PANEL SWITCH ON AND OFF, SWITCHING THE VEHICLE IN AND OUT OF GEAR. SEVERAL TIMES THIS HAS HAPPENED IN SUCH A WAY THAT THE TRUCK SHIFTED INTO 4LO AT MODERATE SPEED. ONCE, THE VEHICLE STALLED IN AN INTERSECTION WITH THE ABRUPT SHIFT. I AM CONVINCED THAT THIS IS A SYSTEMATIC ISSUE WITH GM 4WD TRUCKS, BUT IT IS IN NO WAY BEING ADDRESSED. IT IS AN EXTREME SAFETY HAZARD WHEN A 5400 LB. VEHICLE SUDDENLY SHIFTS INTO LOW RANGE OR NEUTRAL WITHOUT ADVANCE WARNING. A SIMPLE INTERNET SEARCH SHOWS THAT THIS HAS HAPPENED TO MANY OTHER GM VEHICLE OWNERS. THE ONLY REMEDY SEEMS TO BE REMOVING THE RELAY TO CUT POWER TO...