2003 GMC Yukon Powertrain & Transmission Problems

The contact owns a 2003 GMC Yukon. The contact stated that while driving at various speed, the vehicle would stall as the battery warning light appeared on the instrument panel. The contact also stated that the vehicle would shake upon depression of the brake pedal without warning. The vehicle was taken to the independent where the vehicle was purchased and was offered no assistance. The dealer nor the manufacturer had yet to be notified of the failure. The vehicle had yet to be repaired. The failure mileage was approximately 200,000.

REDUCED ENGINE POWER MODE ON HWY AT 70 MPH

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.

TL* THE CONTACT OWNS A 2003 GMC YUKON. WHILE DRIVING APPROXIMATELY 50 MPH, THE VEHICLE EXPERIENCED INDEPENDENT DECELERATION AND THE REDUCED ENGINE POWER WARNING INDICATOR ILLUMINATED. THE VEHICLE WAS PREVIOUSLY TAKEN TO AN INDEPENDENT MECHANIC WHO DIAGNOSED THAT THE FUEL PUMP, SPARK PLUGS, TRANSMISSION, AND ALTERNATOR NEEDED TO BE REPLACED. THE VEHICLE WAS REPAIRED, BUT THE FAILURE RECURRED. THE MANUFACTURER WAS NOTIFIED AND TRANSFERRED THE CONTACT TO NHTSA. THE FAILURE MILEAGE WAS APPROXIMATELY 100,000.

WHILE SITTING IDLE MY VEHICLE SUDDENLY WENT INTO REDUCED ENGINE POWER MODE. I WAS ABLE TO GET OVER AND PULL OFF THE ROAD AND SHUT OFF THE CAR. 5 MINUTES LATER THE CAR STARTED LIKE THERE WAS NO PROBLEM. OVER THE NEXT FEW DAYS THE REP WARNING WOULD SHOW UP AND MY CAR WOULD SUDDENLY LOSE POWER. I WAS CROSSING THE ROAD DURING ONE INCIDENT. HOWEVER, WHEN I WOULD SHUT OFF THE CAR AND RESTART THE CHECK ENGINE LIGHT WOULD GO AWAY AS WOULD THE REP WARNING. AFTER A QUICK REVIEW ONLINE IT IS EASY TO FIND HUNDREDS OF PEOPLE WHO HAVE A SIMILAR ISSUE. GM WILL ONLY DIAGNOSE AND IF THE LIGHT IS OFF WHEN YOU GET THERE THERE IS NOTHING FOR THEM TO DO EXCEPT TAKE YOUR MONEY AND SAY GOOD LUCK.

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

I WAS DRIVING DOWN INTERSTATE 55 COMING FROM SIKESTON MO HEADED TO ST LOUIS WITH MY FAMILY. AS I WAS DRIVING I HEARD A LOUD BANG AND THE TRUCK HAD BEGUN TO VIBRATE AFTER PULLING OF I NOTICED THAT THERE WAS FLUID LEAKING OUT. I HAD TO HAVE THE TRUCK TOWED BACK THE MECHANIC ASSUMED THAT THE TRANSFER CASE WAS GONE OUT BUT UPON REMOVING THE TRANSFER CASE IT WAS THE TRANSMISSION ADAPTER HAD SHATTER I HAD MANY DEALERS LOOK AT THE PIECE AND THEY SAID THEY HAVE NEVER SEEN NOTHING LIKE IT. THE METAL GAVE AWAY FOR NO APPARENT REASON NOTHING ELSE WAS DAMAGED EXCEPT THAT TRANSMISSION ADAPTER. IT WAS FRIGHTENING FOR MY FAMILY AND MYSELF I WOULD LIKE SOME ANSWERS ON WHY THIS HAPPENED THANK YOU SO MUCH *TR

INTERMITTENTLY AT HWY AND SIDE ROAD SPEEDS, TRUCK WILL SHUT DOWN, CHECK ENGINE LIGHT COMES ON AND EXTREMELY ROUGH IDLE AND LOSS OF ENGINE POWER OCCURS. HAVE FOLLOWED ALL RECOMMENDED FIXES BUT PROBLEM PERSISTS. ENGINE CODE 1516, THROTTLE POSITION SENSOR OUT F RANGE +- .05 VOLTS. SCARY PROBLEM, AS THIS OCCURS WITHOUT WARNING AND CAUSES IMMEDIATE LOSS OF SPEED. MANY MANY COMPLAINTS POSTED ON THE INTERNET OF THIS SAME PROBLEM BUT NO GMC RECOMMENDED FIXES OR ASSISTANCE. REFUSE TO TAKE THIS TO A DEALER AND LET THEM POKE AROUND AT $95 / HOUR AND OR TO THROW PARTS AT TRUCK IN HOPES OF CORRECTING. GMC NEEDS TO ADDRESS THIS POTENTIALLY FATAL PROBLEM. *TR

TL* THE CONTACT OWNS A 2003 GMC YUKON DENALI. THE CONTACT STATED THAT THE VEHICLE DECELERATED AND STALLED. THE REDUCED ENGINE POWER INDICATOR ILLUMINATED. THE VEHICLE WAS TAKEN TO THE DEALER SIX TIMES TO REPAIR THE THROTTLE BODY, PEDAL SWITCH, AND WIRING HARNESS, BUT THE FAILURE RECURRED. THE FAILURE MILEAGE WAS 220,000. UPDATED 10/02/14*LJ UPDATED 3/9/2015 *JS

VEHICLE POWERS DOWN WITHOUT ANY PATTERN, RHYME OR REASON. IT WILL DO IT AT 5 MPH, AND AT 55 MPH, WHEN DRIVEN A LOT, AND WHEN NOT. REDUCED ENGINE POWER LIGHT TURNS ON, VEHICLE SUDDENLY SLOWS TO 25 MPH MAX, STEERING BECOMES HARD, BRAKES TOO. THEN WILL TOTALLY SHUT OFF IMMEDIATELY. I HAVE REPLACED THE BATTERY, THROTTLE BODY ASSEMBLY AND WIRING HARNESS TWICE. FUSES, FUEL PUMP AND FILTERS, OIL, AND EVERYTHING ELSE AS RECOMMENDED. IT PUT ME IN THE DITCH. IT STRANDED ME IN THE CENTER OF A FREEWAY IN WINTER. WHEN IT SITS FOR A WHILE, IT RESETS, ONLY TO DO IT AGAIN. T/C LIGHT TURNS ON ALSO. I FOUND OUT THAT I CAN MANUALLY RESET THE REDUCED ENGINE POWER FOR A FEW MOMENTS (TO GET OUT OF THE CENTER OF THE ROAD) BY TURNING THE IGNITION SWITCH ON AND OFF VERY FAST. IT IS A EXTREME SAFETY HAZARD! I HAVEN'T DRIVEN IT IN MONTHS DUE TO ABSOLUTE FEAR FOR MY LIFE. WHEN ITS IN REDUCED ENGINE POWER MODE, I CAN'T GET IT TO GO ABOVE 25, AND GOING UP HILLS CAN'T GO ABOVE 5MPH. IF I AM PULLING A TRAILER, IT STARTS TO GO BACKWARDS. THIS THING IS GOING TO KILL SOMEONE! PLEASE HELP *TR

WE WERE DRIVING AT HIGHWAY SPEED AND LOST POWER WITH NO WARNING. I COASTED TO THE SIDE OF THE HIGHWAY AVOIDING ONE COLLISION. I HAD IT TOWED BACK TO HOME. THE DEALER HAD TO CLEAN THE THROTTLE BODY. I CONTACTED GM AND ASKED WHERE WAS THIS CLEANING FOR PREVENTIVE MAINTENANCE. THEY COULD NOT ANSWER. I AM FEARFUL FOR OTHERS WHO HAVE THIS TYPE OF VEHICLE. WITHOUT CLEANING THE THROTTLE BODY OTHERS WILL HAVE THIS PROBLEM TOO. I WENT TO SEVERAL INTERNET FORUMS AND MANY OTHERS HAVE STATED THIS PROBLEM. HTTP://TOWNHALL-TALK.EDMUNDS.COM/DIRECT/VIEW/.F0E807E/227 PLEASE HELP! [XXX] INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6). *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

2003 GMC DENALI FRONT TRANSFER CASE FAILURE. WHILE DRIVING ON THE HIGHWAY I NOTICED A LOUD NOISE FOR A FEW SECONDS, THEN IT STOPPED, SO I DROVE ON HOME AND THE NEXT MORNING I DROPPED IT OFF AT MY PERSONAL REPAIR SHOP. TO HIS FINDINGS IT WAS THE FRONT TRANSFER CASE. SO HE CALLED THE LOCAL DEALERSHIP AND TALKED TO SOMEONE HE KNEW THAT WORKED AT THE DEALERSHIP IN THE PARTS DEPARTMENT AND THEY TOLD HIM THAT THE DEALERSHIP HAD REPAIRED SEVERAL DENALI'S WITH THE SAME OR SIMILAR PROBLEM JUST THIS YEAR. *JB

TL*THE CONTACT OWNS A 2003 GMC YUKON DENALI. THE CONTACT STATED THAT EVERYTIME HE ACTIVATED HIS LEFT TURN SIGNAL, THE HAZARD WARNING LIGHTS WOULD ILLUMINATE. SECONDLY, THE GAUGES ON THE INSTRUMENT CONTROL PANEL WERE INOPERATIVE. THIRDLY, THE BATTERY CONSTANTLY FAILED WITHOUT WARNING. LASTLY, WHEN SWITCHING GEARS ON THE VEHICLE, THE CONTACT HEARD A LOUD KNOCKING NOISE. HE TOOK THE VEHICLE TO THE DEALER ON NUMEROUS OCCASIONS AND A TECHNICIAN REPLACED THE BATTERY AND ALTERNATOR TWICE, AND THE ENTIRE INSTRUMENT CONTROL PANEL AS WELL. EVEN AFTER ALL OF THE REPAIRS WERE MADE, THE ELECTRICAL FAILURES STILL PERSIST. THE MANUFACTURER DID NOT PROVIDE ANY ASSISTANCE. THE FAILURE MILEAGE WAS 33,000 AND CURRENT MILEAGE WAS 47,400.

WHEN THE VEHICLE'S IGNITION IS IN THE ACCESSORY POSITION THE TRANSMISSION CAN BE SHIFTED INTO REVERSE, NEUTRAL, DRIVE, ETC. WITHOUT THE BRAKE PEDAL BEING PRESSED. MY 3 YEAR OLD WAS SITTING IN MY LAP IN THE DRIVERS SEAT IN A PARKING LOT LISTENING TO THE RADIO IN ACCESSORY MODE HE PULLED THE GEAR SELECTOR DOWN INTO NEUTRAL AND THE CAR BEGAN TO ROLL. THINKING THAT THIS WAS NOT POSSIBLE, I TOOK THE VEHICLE INTO THE DEALERSHIP. THEIR REPLY, "OH THAT'S WEIRD, I DIDN'T KNOW IT WOULD DO THAT". NO FIX, JUST, "WE WILL LOOK INTO IT". *JB

VEHICLE WAS SHUT OFF WHEN CONSUMER'S CHILD SHIFTED THE GEAR SHIFT FROM PARK INTO DRIVE. THIS CAUSED THE VEHICLE TO DRIFT DOWN ON THE ROAD AND HIT A PARKED VEHICLE. *AK THE NEW IGNITION SYSTEM DID NOT ALLOW THE CONSUMER TO TURN THE KEY TOWARD THE DRIVER FOR ACCESSORY USE WHEN THE ENGINE WAS OFF AND IN PARK. WHEN IN ACCESSORY MODE, THE BRAKES DID NOT HAVE TO BE APPLIED TO SHIFT THE GEARS. THIS INCIDENT OCCURRED AS THE CONSUMERS CHILD HAD GOTTEN OF HIS CAR SEAT AND CLIMBED TO THE DRIVERS SEAT. *SC

DT: THE CONTACT STATED WHEN MAKING TURNS THERE WAS A SCREECHING NOISE COMING FROM THE REAR OF THE VEHICLE. IN SNOWY CONDITIONS WHEN THE FOUR WHEEL DRIVE WAS ENGAGED THERE WAS DIFFICULTY DRIVING FOLLOWED BY ANOTHER SCREECHING NOISE WHEN SHIFTING FROM AUTOMATIC TO FOUR WHEEL DRIVE. THE VEHICLE HAS BEEN TO THE DEALER FOR INSPECTION. THE DEALER OVERHAULED THE FOUR WHEEL DRIVE, BUT NOTED ALL FOUR TIRES WERE OFF BALANCE AND VARIED IN SIZE. THIS COULD POSSIBLY BE THE CULPRIT OF THE SCREECHING NOISE WHEN TURNING. THE TIRES HAVE NOT BEEN REPLACED. *AK

WHEN SHIFTING VEHICLE INTO PARK THERE IS A LOUD POPPING NOISE, INDICATING TRANSMISSION FAILURE. *AK