2020 GMC Sierra 1500

These are unverified consumer reports filed with NHTSA, shown as submitted.

• 12/30/2020· POWER TRAIN,SERVICE BRAKES

  CAR WAS IDLING AND PARKED. WARNING CODE SHOWED UP ON DASHBOARD ESC, ELECTRONIC STABILITY CONTROL, REDUCED ENGINE POWER. VEHICLE THEN DISPLAYED TRANSMISSION DISRUPTION, WARNING LIGHT DISPLAYED AS WELL. I WAS ABLE TO DRIVE IT TO THE DEALERSHIP BUT THE PERFORMANCE OF THE VEHICLE WAS LIMITED BY THE REDUCED ENGINE POWER. TRANSMISSION WAS HESITATING AND CLUNKY DURING GEAR CHANGES. MY SIERRA HAS 5,000 MILES ON IT AND THE TRANSMISSION WAS ALREADY REPLACED AT 2,000 MILES. GMC HAS A SERIOUS PROBLEM WITH THIS MAKE AND MODEL. UNSURE WHAT THE RESOLUTION WILL BE, BUT I AM NO LONGER CONFIDENT IN THE PRODUCT GMC IS SELLING.

• 12/29/2020· AIR BAGSCrash

  TL* THE CONTACT OWNS A 2020 GMC SIERRA 1500. THE CONTACT STATED THAT WHILE DRIVING APPROXIMATELY 35 MPH THE DRIVER LOST CONTROL OF THE VEHICLE AND DROVE OFF THE ROAD AND DOWN AN EMBANKMENT BEFORE CRASHING TO THE GROUND. DURING THE CRASH THE VEHICLE SUSTAINED SEVERE DAMAGE TO THE FRONT END BUT THE AIR BAGS DID NOT DEPLOY. THE DRIVER SUSTAINED HEAD AND SHOULDER INJURIES WHICH REQUIRED MEDICAL TREATMENT. THE VEHICLE WAS TOWED AWAY. NO POLICE REPORT WAS TAKEN. THE CAUSE OF THE FAILURE WAS NOT DETERMINED. THE LOCAL DEALER MAYSE EARNHARDT AUTO GROUP LOCATED AT 2032 S ELLIOTT AVE, AURORA, MO WAS NOTIFIED OF THE FAILURE. THE MANUFACTURER WAS NOT CONTACTED. THE FAILURE MILEAGE WAS 10,000.

• 12/28/2024· FUEL/PROPULSION SYSTEM

  GDI fuel pump went bad needed replacement.

• 12/27/2022· VEHICLE SPEED CONTROL,SERVICE BRAKES

  i was stopped at a red light and when the light turned green I accelerated and the vehicle shut off and then came back on. when the vehicle came on i had a service esc light and a system break failure warning telling me not to exceed 62mph. i made it back to my house driving with extreme caution. the breaks were very delayed while driving.

• 12/26/2025· ENGINE,FUEL/PROPULSION SYSTEM

  I started to notice changes in performance around 75k miles. Seemed like performance was subpar compared to what was the norm. Seemed to lose some power. Minimal at first, more so just recently around 90k. Oil consumption was starting to accelerate at each oil change at 75k, 80k, 85k, 90k. To the point around 85k and 90k that I would not go over even 1 mile from the 5k threshold without changing the oil. Around 90k I could tell it was not getting any better, deficiencies were accelerating it seemed. At 91k miles I started to hear clicking noises and loss of power, starts were getting rough, bouncing at idle. I stopped driving it, only driving it to the dealership where I brought for a look at it. Will be driving it again for them to do a deeper diagnostic. Many misfires at cylinder 5. PO305 the issue. Showed up around 91k miles on 12/17/25 Now investigation into my model. I see online.

• 12/20/2020· ELECTRICAL SYSTEM,SERVICE BRAKES

  ON TWO SEPARATE OCCASIONS, THE TRUCK HAS BEEN DEAD WHEN ATTEMPTING TO CRANK. THERE WERE NO LIGHTS OR DEVICES LEFT ON AFTER THE PREVIOUS TIME THE TRUCK HAD BEEN USED. SOMETHING IS DRAWING POWER FROM THE BATTERY CAUSING IT TO BE DEAD. AFTER RECHARGING THE BATTERY, THE CHECK ENGINE CODES READ THAT THERE IS A PROBLEM WITH 'BRAKE LIGHT ILLUMINATION.' HELP IN DETERMINING WHA T IS CAUSING THE BATTERY TO DIE ON SUCH A NEW VEHICLE WOULD GREATLY APPRECIATED! I'M UNCERTAIN AT THIS TIME AS TO WHETHER OR NOT THE BRAKE LIGHT ILLUMINATION IS CAUSING A SAFETY HAZARD.

• 12/19/2025· ENGINE AND ENGINE COOLING,ENGINE

  The contact owns a 2020 GMC Sierra 1500. The contact stated that while driving approximately 35 MPH, the vehicle lost automotive power with the check engine warning light illuminated and the message "Vehicle Might Lose Power" displayed. The vehicle remained at the residence, and the contact used a self-diagnostic tool to retrieve a fault code related to the coolant valve D. The contact determined that the coolant valve D needed to be replaced. The vehicle was taken to an independent mechanic; however, the contact was unaware of the part that needed to be fixed in the vehicle. The vehicle was repaired. The contact researched and was made aware of an unknown NHTSA Campaign Number; however, the VIN was not under recall. The manufacturer was contacted and confirmed that the VIN was not under recall. The failure mileage was approximately 31,000.

• 12/19/2023· UNKNOWN OR OTHER,VISIBILITY/WIPER

  The rear window was leaking a substantial amount of water soaking the back seat. Had the service bulletin done, which did not work. Then under further inspection found cracks in the rear power window track. Dealer told me GM would not cover replacement because it was out of the 3 year warranty. Then was told it would cost me 1200 dollars to replace. GM should cover this because it will lead to black mold.

• 12/18/2025· ENGINE,FUEL/PROPULSION SYSTEM

  Fuel management system caused a lifter to fail (stuck) which resulted in camshaft damage at 77,611 miles. GM refused to cover the repair, although there is a pending class action lawsuit against GM for this very issue. Truck was repaired at a GM dealership - Sunrise Collierville, TN. Repair costs was approximately $7,000. This occurred during a 2.5 hour road trip which put lives at risk. The truck began to vibrate, and the check engine light came on. There was no other warning before the failure occurred. No police or insurance were involved. This occurred on 9/27/25. It took the dealership 32 days to diagnose and repair the issue. Thanks.

• 12/16/2024· POWER TRAIN

  The contact owns a 2020 GMC Sierra 1500. The contact received notification of NHTSA Campaign Number: 24V797000 (Power Train); however, the part to do the recall repair was unavailable. The contact stated that the manufacturer had exceeded a reasonable amount of time for the recall repair. The contact stated that there was a loud clanking sound underneath the vehicle while starting the vehicle. There were no warning lights illuminated. The vehicle had been taken to the dealer and was diagnosed with transmission failure. The contact stated that the transmission had been repaired twice however, the failure persisted. The vehicle was taken to the dealer again and the transmission was replaced. The dealer was contacted about the recall and confirmed that the VIN was included in the recall however, the part to do the recall repair was not yet available. The manufacturer was not made aware of the issue. The failure mileage was 50,000. Parts distribution disconnect.

• 12/15/2025· POWER TRAIN

  While driving on the interstate at 70 mph, the transmission began to shudder. It continued the duration of the trip of 90 mins. Following day, the transmission is continuing to shudder and is now shifting hard.

• 12/15/2022· FUEL/PROPULSION SYSTEMCrash

  The fuel pump module failed according to the dealer at 34000 miles . Car stop while driving. Cranks but no start. After resting it for hours I was able to start. Drive couple of miles about 39000 miles it stops middle of driving and couldn’t start anymore but still cranks

• 12/15/2019· EXTERIOR LIGHTING

  WHEN MAKING RIGHT TURNS IN THE DARK THE HEADLIGHTS DO NOT CAST LIGHT TO THE RIGHT SO YOU CAN SEE WHERE YOU ARE TURNING. THIS IS ESPECIALLY A PROBLEM IN THE RURAL WITHOUT STREETLIGHTS IT IS TOTALLY BLACK FROM THE DRIVERS SEAT LOOKING OVER THE RIGHT SIDE OF THE HOOD OR OUT THE RIGHT WINDOW.

• 12/13/2025· ELECTRICAL SYSTEM,VISIBILITY/WIPER

  The morning of December 12th, 2025 I used my vehicle to transport my daughter approximately 5 miles round trip from our home to drop her off at daycare and then I returned home. I used my front and rear defrost elements to expedite removal of heavy condensation which had formed on all windows overnight. This was approximately 7 AM. I parked my truck in the driveway and went inside until approximately 11:45 AM when I went to leave in my truck and noticed the rear sliding window had shattered. The window shattered and distributed tempered glass fragments all over the inside of the cab. Only approximately 10% of the window remained intact. I then reviewed the security camera footage from my driveway and discovered that the window failed entirely on its own with nothing hitting/striking/touching the window, nor any humans or animals in the vicinity. I attempted to take the vehicle to a GMC service department this morning (Dec 13) but due to their demand to keep the vehicle for 2-3 days to investigate yet unable to provide a loaner vehicle, I was unable to leave the vehicle in their possession and returned home. I plan to continue to contact GMC dealership service departments in hope I can find one which can provide a loaner vehicle, as I will need transportation to and from work in the coming days. I do have video footage of the incident although I am unable to add it below.

• 12/12/2024· BACK OVER PREVENTION

  The contact owns a 2020 GMC Sierra 1500. The contact stated while reversing the vehicle, the rearview camera image failed to display as needed, and the radio was inoperable. The vehicle was taken to the dealer, but the cause of the failure could not be determined. The vehicle was not repaired. The manufacturer was made aware of the failure and a case was opened. The failure mileage was approximately 3,500.

• 12/10/2024· SERVICE BRAKES

  My pickup was specifically purchased to pull a duel axle trailer ( brakes required by Fl. Law). The trailer weights more than the pick up. They stopped working with the electric /hydrolic Trailer brake system. I have had the Sierra in three times for Warren Ty repair. They never fixed the system. I have thoroughly test the trailer system - it works fine with another pickup. Dealer won’t return my calls. Multiple trips taking it in for this problem. Have a case filed with GM. All just placating me, now ignoring my problem. I am stuck and they are not acting in good faith.

• 12/10/2020· ELECTRICAL SYSTEM,SERVICE BRAKES

  AFTER HAVING ALL SORTS OF WARNINGS OVER TIME LIKE "SERVICE ESC," "SERVICE PARKING BRAKE," AND MORE, I NOW SEE "BRAKE SYSTEM FAILURE: 62 MPH TOP SPEED" FLASH ACROSS MY DASH. I AM READING AND HEARING THAT THIS IS A VERY DANGEROUS PROBLEM. NEW TRUCK. BRAND NEW. HAD IT LESS THAN A YEAR. BRAKE MESSAGE ALWAYS ON START UP.

• 12/08/2025· ENGINE

  In December of 2023 my 2020 GMC Sierra 1500 was driving down the freeway, experienced a jerking and low oil pressure. Pulled over and shut vehicle off and wouldn't turn back on, engine locked up. The vehicle received a brand new 6.2l replacement motor in April of 2024- $15k in parts and labor. This vehicle was not included in the recent recall, but obviously experienced a similar issue. This was at 75k miles. The car was owned by a different owner at the time of the engine failure. I bought the vehicle as a repo and proceeded to get the engine fixed on it.

• 12/08/2025· ELECTRICAL SYSTEM,ENGINEFire

  The contact owned a 2020 GMC Sierra 1500. The contact stated that after the vehicle was purchased and while driving at an undisclosed speed, the check engine warning light illuminated. The dealer was contacted. However, the check engine light turned off, and the dealer refused to inspect the vehicle. The contact stated that while driving at an undisclosed speed, the vehicle jerked and the check engine light illuminated. The dealer was contacted. However, the warranty had expired, and the dealer refused to inspect the vehicle. The manufacturer was contacted, and the contact was offered a five-hundred-dollar coupon. The vehicle was taken back to the dealer. However, no cause for the failure was found. The contact stated that an unknown part was replaced. The contact stated that the failure persisted. The contact stated that while turning on the engine, the contact's sister informed him that smoke was emitting from under the hood. The contact turned off the engine, opened the hood, and noticed that all of the wires were melted. The contact splashed water on the wires. The contact checked underneath the vehicle and noticed that the plastic that was burnt was leaking residue. The vehicle was left at the residence where the contact's mother lives. The next day, the contact noticed that the front windshield had shattered due to the heat from the burnt wires. The insurance company was notified and referred the caller to take the vehicle to be inspected. The vehicle was towed to a collision center. The contact was informed that the vehicle had a factory defect. The vehicle was not repaired. The manufacturer was notified of the failure. However, no assistance was provided since the warranty had expired.  The failure mileage was approximately 32,000.

• 12/07/2025· ENGINE

  Engine lost all power while driving highway speed. Vehicle towed to Cavender Chevrolet dealer in Boerne, TX. Dealer inspected and determined cam bearings damaged. Engine replaced with remanufactured engine.

• 12/06/2021· ENGINE

  The contact owns a 2020 GMC Sierra 1500. The contact stated that shortly after refueling while driving under 15 MPH, the check engine and service emissions warning light illuminated. The contact stated that an unknown reset was performed related to TSB: 10173675 (Engine). The vehicle was not yet fully repaired. The manufacturer was made aware of the failure. The approximate failure mileage was 46,000.

• 12/04/2025· POWER TRAIN,ENGINE

  MY 2020 5.3 L GMC AT4 IS EXPERIENCING LOSS OF POWER WITH BUCKING & STALLING. CYLINDERS ARE NOT ACTIVATING WHEN CALLED CHECK ENGINE LIGHT IS FLASHING, IT STARTS ROUGH AND MAKES NUMEROUS NOISES AT VARIOUS SPEEDS, AS WELL AS AT IDLE. SO I BROUGHT MY VEHICLE TO MY LOCAL AUTO REPAIR SHOP. OUR MECHANIC FOUND TWO FAILED FUEL INJECTORS AND A FAILED THROTTLE BODY. THEN THE LOUD KNOCKS IN MY BLOCK FAILED AN ACOUSTIC TEST. HE ALSO DETERMINED THE LIFTERS, PUSH RODS AND CAMSHAFT ARE EXPERIENCING EXCESSIVE WEAR. THE AFM SYSTEM HAS FAILED! HE WARNED ME THAT FURTHER USE OF MY MOTOR (WITH ONLY 42K MILES ON IT) WILL CAUSE A CATASTROPHIC FAILURE. MY RESEARCH SHOWS THAT THESE ISSUES ARE BECOMING COMMON OF 5.3 GMC MOTORS. WE SEARCHED THE COUNTRY FOR A REBUILT MOTOR AND FOUND THAT NONE ARE AVAILABLE FOR THE NEXT SEVERAL MONTHS. HOWEVER, I WAS ABLE TO FIND A NEW MOTOR AT MUCH GREATER COST. GMC HAS DECLINED ASSISTANCE AT THIS TIME. MY VEHICLE HAS NO VALUE AS IS, SO I ORDERED THE NEW GM ENGINE. WITHOUT THE DOD SYSTEM, THESE ENGINES WERE DESIGNED TO GO WELL OVER 100,000 MILES. I AM A FAITHFUL GMC OWNER AND NONE OF MY PREVIOUS GMC TRUCKS (2003, 2013, 2015, 2019) HAD SUCH A MAJOR PROBLEM. NOW THE 2020'S FUEL SAVING SYSTEM HAS FAILED AND REQUIRES REPAIRS THAT AMOUNT TO HALF THE VALUE OF MY TRUCK. WHEN A FULL SIZE TRUCK STALLS ON THE HIGHWAY IT'S CERTAINLY LIFE THREATENING.

• 12/04/2024· ELECTRICAL SYSTEM,STRUCTURE

  Tailgate releases on its own while parked, without the use of the switch. Tailgate released on its own with my trailer attached while parked on many occasions. The result of the Tailgate releasing caused damage to the upper section of the Tailgate, the "kicker speaker system" in the Tailgate and Tailgate switch located on the upper section of the Tailgate. There also have been multiple times when attaching the trailer that the Tailgate has released and struck me in the head. The Tailgate also fills with water during rain, and carwashes. The damage caused by the Tailgate releasing is a dent on the upper section of the multi-pro Tailgate and rust and malfunction of the " kicker speaker system " as well as the occasional hickey and headache on my head. The Tailgate has filled up with water since I purchased it new in December of 2020 which I believe has been electricly shorting the Tailgate switch/button releasing the Tailgate randomly. Due to my particular 2020 GMC Sierra 1500 AT4 CarbonPro having the " kicker speaker system " in my opinion makes the Tailgate so much heavier than one without it that it made the damages such as the dent in the face above the Tailgate switch much worse than trucks without it also causing more water to enter the Tailgate causing more damage to the switch and components of the " kicker speaker system ", such as the amp and buttons for it not to mention my head on several occasions.

• 12/04/2024· POWER TRAIN,VEHICLE SPEED CONTROL,FUEL/PROPULSION SYSTEM

  Shuttering while in motion at a speed of 35mph or above. My 2020 GMC SIERRA 1500 AT4 CarbonPro while driving at or above speeds of 35mph experiences a hesitation and severe Shuttering while trying to maintain any speed of 35mph or above. The hesitation causes extreme vibrations and hesitation when lifting or applying foot to the accelerator. This happens in any drive mode also with cruise control on or off as well as shifting into low and being in any gear trying to prevent it. It also does this on any road and condition. It feels like a slip in the transmission or torque converter, possibly could be the rear end or variable valve timing as well. And when taking of from a red-light or stop sign it slips as if the truck has lost traction, but it hasn't. This is very dangerous and could be the cause of a serious accident when trying to accelerate. If your traveling at hwy speeds it feels as if the brakes are being applied and the tires are going over a washboard which could cause a collision, tire wear, or driveline damage.

• 12/04/2020· ELECTRICAL SYSTEM,ENGINE

  THERE IS NO WAY TO PERMANENTLY DISABLE THE AUTO START STOP ON THE VEHICLE. SEVERAL OTHERS HAVE COMPLAINED ABOUT THIS, NO RESPONSE FROM GM. THERE NEEDS TO BE A FIRMWARE UPGRADE TO THE ECM TO ALLOW THE OWNER MAKE THE DECISION ON IF THAT IS ENABLED OR DISABLED. ON MINE, I HAVE TO PUSH A BUTTON EACH TIME I START THE ENGINE TO DISABLE THAT. SOME GM VEHICLES DON'T HAVE THAT OPTION.

• 12/01/2025· ENGINE

  Driving on the Highway, the engine shuttered, but kept going. When I had to slow down, the engine stalled and would not restart. It left me in the center lane of a three lane highway. I was able to push the vehicle off to the side of the road. Very dangerous. No warning lights came on, no alerts. I had the truck towed to Folsom Buick & GMC in Folsom CA where the diagnosed a complete engine failure. The have now had my truck for a full month. They are trying to get GMC to share the cost of the replacement motor. In the meantime, I'm renting a pickup truck so I can continue to work.

• 12/01/2025· POWER TRAIN,ENGINE

  Ticking noise coming from engine slight metallic noise as well. RPMs drop and when they drop, you can feel power loss constant hunting in the RPMs. Also a weird vibration, not all the time in the front end somewhere.

• 11/27/2023· ENGINE

  timing chain failure, timing chain components are available for inspection. Costly premature repair/failure. Could leave occupants stranded in unsafe environment which could lead to death. The vehicle has been diagnosed by the dealership and OEM manufacturer has been notified. There was a warning lamp.

• 11/25/2025· POWER TRAIN,ENGINE

  -lifter failure on 6.2 v8 engine, causing damage to camshaft -lost significant propulsion while driving on the highway, nearly avoided being rear-ended by another vehicle due to loss of vehicle propulsion -dealer had to to replace lifter bank and camshaft -no issues, once lifter failed dash lights all lit up

• 11/25/2025· SERVICE BRAKES, HYDRAULIC,ENGINE AND ENGINE COOLING

  The contact owns a 2020 GMC Sierra 1500. The contact stated while driving 45-50 MPH, the check engine warning light and the brake warning light illuminated. Additionally, the contact heard an abnormal sound coming from the engine, and the vehicle decelerated. The vehicle was taken to the dealer, where it was diagnosed and determined that all the engine lifters and the camshaft needed to be replaced. The vehicle was repaired. The contact related the failure to NHTSA Action Number: EA25007 (Engine and Engine Cooling). The manufacturer was notified of the failure and informed the contact that the VIN was not under recall. The manufacturer offered to partially cover the cost of the repair. The failure mileage was 107,787.

• 11/24/2025· ENGINE

  Engine fan has been constantly running, with engine temp reading around 230 consistently. After driving 5 miles on the interstate it shot up to 260 and said “engine temp overheating, idle engine”.

• 11/22/2025· ENGINE

  I am Having direct issues with the engine when the vehicle is started and continues while idling or driving at any rate of speed.There's a continuous "Knocking" noise that has concerned me for a while now. My vehicle (2020 GMC Sierra 6.2 liter gas engine) with almost 100,000 miles has been doing this for a while now (at approximately 50,000 miles) and (was documented at the dealership when I made a complaint which included what I considered the vehicle to be using/losing more "oil consumption" than the normal 3-4 quarts between oil change) dating back to 2022 0r 2023 when I was told by the dealership that the amount of oil being used/ lost still fit within the manufacturers specifications.

• 11/21/2021· SUSPENSION

  At 8,000 miles I started hearing a clunking noise in my truck when I hit a small bump or back up out of drive way. Brought in and GMC stated it was normal and no issues at walser buick gmc of Roseville. Brought I back again because it was getting worse and could hear it every time I slowed down and accelerated. Then stated they need to order spacer bushings at walser of Bloomington. Then went back for 3rd time and installed them at Bloomington.After 600miles noise was back and is getting worse again. I called Walser of Bloomington again and said I need to drive it for 1000 miles to break in spacers. So now we have 11,000 miles on truck with same noise again and its going back again because needs to get fixed. GMC is just asking for something to happen. Also when this first happened at 8,482miles I was on 35w and the rear end started wobbling and gave me a small death wobble but I slowed down to control it. That’s when I brought it in and it could of hurt or killed somone.

• 11/20/2025· POWER TRAIN

  My truck had engine failure while at the dealership getting new tires installed on 11/12/2025. When they started my truck they detected major knocking in my engine the 1st thing in the morning. It unsafe to drive they're telling me my engine needs to be replaced. My engine has 58,000 miles on it. There was no issues with my truck when I drop it off.

• 11/20/2020· ENGINE

  TL* THE CONTACT OWNS A 2020 GMC SIERRA 1500. THE CONTACT STATED THAT THE VEHICLE PUSH START BUTTON AND KEY FOB FAILED TO START THE VEHICLE ON FIRST ATTEMPT. THE CONTACT STATED THAT THE VEHICLE STARTED AFTER SEVERALS ATTEMPTED. THE CONTACT STATED THE FAILURE OCCURRED INTERMITTENTLY. THE CHECK ENGINE WARNING LIGHT ILLUMINATED. THE CONTACT STATED THAT ON HIS WAY TO MCKENZIE BUICK-GMC DEALER, 6500 CAROLINE ST, MILTON, FL 32570, THE CHECK ENGINE WARNING LIGHT WAS NOT ILLUMINATED, THE VEHICLE WAS DIAGNOSED AND THE CONTACT WAS INFORMED THAT A FAILURE CODE WAS NOT FOUND. THE VEHICLE WAS NOT REPAIRED. HOWEVER, THE CONTACT CALLED BACK THE SAME DEALER AND INFORMED THEM THAT THE FAILURE RECURRED. THE VEHICLE WAS NOT YET TAKEN BACK TO THE DEALER. THE MANUFACTURER WAS NOT MADE AWARE OF THE FAILURE. THE FAILURE MILEAGE WAS APPROXIMATELY 86.

• 11/19/2025· UNKNOWN OR OTHER

  Safety Recall N242454440 Momentary Rear Wheel Lock-Up was issued for 2020 to 2022 GMC Sierra 1500 but mine is not included. I drive a 2020 GMC Sierra 1500. It is experiencing harsh shifting and now there is a feeling in the rear wheels like they are trying to get stuck or hang up. Why is my truck not included?

• 11/19/2025· ENGINE

  My 2020 GMC Sierra 1500 Denali with the 6.2L L87 V8 just began experiencing a new rough idle with intermittent RPM dips. There are no engine codes or warning lights. Idle drops are noticeable, suddenly began this week. I am concerned due to ongoing NHTSA Engineering Analysis EA25-007 involving this engine. Some owners reported engine failure with little warning. The truck has right over 68,000 miles on it and has had every oil changed performed at a GM dealer. I have had to top off the oil between cycles and always used the recommended oil, being the Dexos Gen 3 due to the truck burning a small amount of oil. More detail on a possible cause. I believe it would be worth investigating the DFM technology. I will be performing a fuel cleaner and possibly a lifter cleaner and/or additive. I would like to tune the truck and turn off the DFM since this is what I have read causes the truck to burn oil and damage the lifters. However, I will wait until this Analysis is completed before deciding to change the truck's stock tunes.

• 11/19/2025· ENGINE

  The engine failed and started burning oil at a rate of 3 quarts every two weeks. The vehicle is currently at the GMC dealership having the engine rebuilt at a cost of over 15,000. The vehicle has approx. 116,000 miles at time of failure, so it is outside of the manufacturers warranty. The GMC dealership (Fred Anderson Greer) has photos. The engine is a 6.2L but not currently under recall as it is a 2020, the recall includes 2021 - 2024 models.

• 11/17/2025· ENGINE

  My engine is currently being torn down at the dealership.I heard a ticking noise coming from my engine so I took to the dealership I bought it from and when they did their diagnostics and inspection they said it was a connecting rod bearing failure.

• 11/17/2025· ENGINE

  This is the 3rd catastrophic engine failure since purchasing this new vehicle from the dealership, the vehicle is currently at the dealership and is available for inspection. The latest diagnostic report has been attached from the dealership for reference. My safety and the safety of others was at risk with each occurrence. The 1st occurred on the interstate when a lifter rod bent causing loss of power with no warning, engine was rebuilt by the dealership. The 2nd occurred on the interstate when a different lifter rod bent causing loss of power with no warning, engine was rebuilt again by the dealership. The 3rd occurred just recently while on a highway. The engine suddenly turned off with no warning. The dash told me to put it into neutral and start again. I had to coast the truck for a long distance after the sudden loss of power in order to attempt to restart the engine. The engine would not start. The diagnostic report from the dealership states "engine is seized tight, maxi fuse is blown, needs engine replacement."

• 11/16/2021· SERVICE BRAKES

  Brakes have been squealing since 4000 mile mark. Dealer states it’s normal.

• 11/15/2025· POWER TRAIN,SERVICE BRAKES,ENGINE

  First my torque converter went out, no warning lights only shaking wehn shifting, I got it replaced already it cost me 2400 Second Warning light service for Brakes, Traction and power steering come on and off. And sometimes truck doesn't brake well and steering wheel feels hard to drive, it has happened while on expressway with family. Third Engine oil low Add oil warning sign comes up alot and I have to add oil, engine has a rough idle now, also when I turn truck on smoke comes out while having a rough idle, recently it started knocking, I haven't moved the truck since than

• 11/14/2024· ENGINE

  The contact's son owns a 2020 GMC Sierra 1500. The contact stated while driving at various speeds, the vehicle shut off without warning. The contact stated that the vehicle was restarted and resumed normal operation moments after the failure. The contact stated that the failure recently started occurring more frequently. The manufacturer was notified of the failure and the contact was provided a case number. The contact was referred to the NHTSA Hotline to report the failure. The vehicle was not repaired. The failure mileage was approximately 40,000.

• 11/12/2025· ENGINE

  This is a report on an incident that happened a year ago. Vehicle was taken to GMC dealer who replaced the engine at our expense. Seems to be consistent with the problem on newer GMC's that have been covered by a recall. This 2020 is one of three GMC's owned by our company. This expense was in the $12,000 range. (The 2019 experienced similar issues in 2022 and the expense was $2800 ish, and in 2024 another $1200 ish. ) Dash lit up like a Christmas tree, all warning lights on. Stalled, barely moved.

• 11/11/2022· STEERING,SUSPENSION

  Drivers side upper control arm failure. Threw truck into oncoming traffic. Dealership has inspected multiple times stating everything was good to go. Been complaining about a loud clunk to dealership for months

• 11/10/2025· ELECTRICAL SYSTEM,UNKNOWN OR OTHER,FUEL/PROPULSION SYSTEM

  1. The vehicle’s emissions system is malfunctioning, specifically the ECM (Engine Control Module) related to the exhaust emissions system. The diagnostic trouble code is P2C7A, indicating the system is not performing as expected. Key components such as the NOx catalytic converters and diesel particulate filter have been repeatedly replaced, but the issue persists. The vehicle and all replaced components are available for inspection upon request. 2. The malfunctioning emissions system has led to an exhaust leak that allowed exhaust gases to enter the vehicle’s cab. This creates a hazardous environment for both the driver and passengers, exposing them to harmful exhaust fumes. In addition to reduced engine performance, poorer fuel economy, and emissions non-compliance, this exhaust leak poses a serious safety risk by compromising the air quality inside the vehicle. Prolonged operation under these conditions could lead to adverse health effects and further mechanical failures that impact vehicle safety. 3. Yes. The dealership has diagnosed the problem multiple times. The emissions components have been replaced under warranty on two separate occasions. The dealer attributed the fault to fuel quality; however, Fuel distributor debunked these claims. 4. The vehicle has been inspected extensively by the dealership with invoiced repair work replacing key emissions control components. 5. The check engine light and Service Engine Soon (SES) light have been illuminated with the diagnostic code P2C7A since the initial identification of the problem which started 3JUN24

• 11/10/2025· ENGINE

  Engine ticking especially when cold, dealership claims they fixed it while it was under warranty but it has continued to do it.

• 11/09/2022· UNKNOWN OR OTHER

  Once vehicle is put in park, the control panel comes and reads, “shift in park and radio and head lights stays on as well”. I exit the vehicle and it continues to display the mention above. I’ve restarted the vehicle and put it back in park still the “shift in park”, stays on. I exit the vehicle and monitored the vehicle for approximately 5 minutes and finally turned off. This never happened before, I’m afraid it may stay on one of these days and run the battery down.

• 11/07/2025· ENGINE

  At approximately 54,000 miles had a complete engine failure. Lifter blew apart and damaged crank shaft. Complete engine rebuild. Rebuilt in approximately 3 weeks. 2022 At approximately 138,000 miles had another complete engine failure. Lifter blew apart again, Entire engine was replaced. New engine took 10 weeks to get. Installed in 2 days after recieved. 2025 No symptoms or warning lights present prior to failure.

• 11/07/2023· SERVICE BRAKES,FORWARD COLLISION AVOIDANCE

  ABS LIGHT LIMITED TO 43 MPH ESC system Steering assist reduced Service Trailer Brake System Engine light on