2003 GMC Yukon Xl 1500

THERE IS AN ERROR MESSAGE THAT DISPLAYS ON THE DASH FOR MYSELF AND THOUSANDS OF OTHERS WHO OWN GMC/CHEVY TRUCKS WITH THESE MOTORS. THEY HAVE A DEFECTIVE THROTTLE POSITION SENSOR WITH THE TRUCK WHERE IT SAYS "REDUCED ENGINE POWER". I'VE FOUND 2 TECHNICAL SERVICE BULLETINS THAT SOMEWHAT ADDRESS THE ISSUE, BUT MANY PEOPLE TAKE THEIR TRUCKS TO MECHANICS AND DEALERSHIPS TO GET THE ISSUE FIXED AND SPEND THOUSANDS OF DOLLARS IN REPAIRS AND TROUBLESHOOTING TO GET THE ISSUE RESOLVED, TO NO AVAIL. THE 2 TECHNICAL SERVICE BULLETINS THAT I FOUND WERE #PIP3089B (DATED 10/31/2006) AND #PIP3042A (DATED 8/30/2004). I'VE SEEN ON MANY MANY FORUM POSTS ABOUT THIS ISSUE AND POSSIBLE FIXES, WHICH WHEN I READ DEEPER INTO THEM, SEEM TO NOT BE TRUE FIXES.

VEHICLE HAS BEEN SERVICED SEVERAL TIMES SINCE FIRST OCCURRENCE IN SEPTEMBER 2014. "REDUCED ENGINE POWER" AND SERVICE ENGINE SOON SIGNALS APPEAR ON VEHICLE PANEL CAUSING ENGINE POWER TO BE REDUCED IN A MATTER OF SECONDS. HAS HAPPENED TO ME GOING 10MPH, 55MPH, AND 70MPH ON HIGHWAY, CAUSING A NEAR REAR COLLISION BECAUSE I LOST POWER SO QUICKLY. I HAVE HAD IT SERVICED 6 OR 7 TIMES SINCE SEPTEMBER 2014 AND THIS ISSUE IS NOT GETTING RESOLVED. THROTTLE BODY SENSOR REPLACED TWICE, THROTTLE BODY HARNESS REPLACED, ALL WIRES, AND SENSORS HAVE BEEN CLEANED AND THOROUGHLY INSPECTED. REDUCED ENGINE POWER OCCURS WEEKLY EVEN AFTER BEING SERVICED. *TR

VEHICLE SUDDENLY AND AUTOMATICALLY SWITCHED FROM 2 WD TO 4 WD LOW. DRIVER DID NOT ENGAGE 4WD LOW SYSTEM WHICH REQUIRES TO 1ST PLACE TRANSMISSION INTO NEUTRAL THEN SELECT 4 WD LOW BUTTON. DRIVER MOMENTARY LOST CONTROL OF VEHICLE (STEERING) BUT WAS ABLE TO SAFELY MOVE VEHICLE TO SIDE OF ROAD. DRIVER AND OCCUPANTS WERE JOINTED FORWARD WITH IMPACT OF ENGAGEMENT OF LOW GEARS AND IMMEDIATE LOSS OF SPEED. *TR

TAKING OFF FROM A STOP OR ACCELERATING FROM A LOW SPEED THE TRACTION CONTROL MESSAGE COMES ON AND VEHICLE LOOSES POWER. HAPPENS SEVERAL TIMES EVERYTIME I DRIVE THE VEHICLE. I HAVE 3 CHILDREN UNDER THE AGE OF 10 THAT HAVE BEEN WITH ME WHEN THIS HAPPENS. I FEAR WE WILL BE INVOLVED IN AN ACCIDENT BECAUSE OF THIS POWER TRAIN FAILURE. DEALER CLAIMS THERE IS NO PROBLEM OR ERROR CODES. *TR

FRONT DIFFERENTIAL FAILS ON AWD VERSIONS OF YUKON/DENALI MODELS. UNUSUAL FRONT DRIVELINE NOISE IS EXPERIENCED ESPECIALLY DURING LIGHT ACCELERATION OR LOAD. NOISE IS A WHINE TYPE OF LOAD. THIS ONE FAILED @ 54,000 CAUSING DEALER TO REBUILD FRONT DIFFERENTIAL WITH NEW BEARINGS AND SEALS. OLD BEARINGS WERE BADLY SCORED AND ONE OF THEM BROKEN TO MANY PIECES. I ASKED FOR PARTS AND WAS GIVEN WHAT COULD BE PULLED OUT. INTERNET SEARCH INDICATES MANY OWNERS WITH AWD SYSTEMS WHICH WERE ALSO AVAILABLE ON YUKON AS WELL AS DENALI MODELS HAVE HAD SIMILAR FAILURES. COST TO REPAIR AS WARRANTY EXPIRED AT 40,000 MILES WAS APPROX. $1000. *TR