2020 GMC Yukon problems

ENGINE

We just purchased our Yukon from a dealership in February (2/7/26) and it was diagnosed with premature failure of at least one AFM valve lifter as it is causing engine misfires, shaking and stalling on 7/30/26. We just hit 67,000 miles on the odometer so we are just beyond the warranty coverage. The lifters were replaced previously by the previous owners on 12/16/24.

NHTSA complaint #11758957 — an unverified report by a vehicle owner.

POWER TRAIN

The contact owns a 2020 GMC Yukon. The contact stated that while driving at various speeds, the vehicle jerked and the transmission malfunctioned, causing the wheels to lock up and the check engine warning light to illuminate. The vehicle was driven to a local dealer who diagnosed that the transmission clutch and pressure control solenoid had failed. The contact was advised that the transmission needed to be replaced. The vehicle was not yet repaired. The manufacturer was notified of the failure, but no assistance was offered. The contact was informed that the VIN was not included in NHTSA Campaign Number: 26V289000 (Power Train). The contact stated that the vehicle experienced the same failure listed in the recall. The failure mileage was 118,000.

NHTSA complaint #11749486 — an unverified report by a vehicle owner.

POWER TRAIN

Complete transmission failure at 82,000 miles. Well maintained vehicle, not used for towing or heavy hauling. Required complete replacement. Traveling at highway speeds and-according to repair facility- valve failure caused transmission to overheat a stripped gears, causing complete failure. Vehicle was unable to shift into any gears and was left inoperable. Required towing assistance and replacement.

NHTSA complaint #11748691 — an unverified report by a vehicle owner.

WHEELS

Issue with the trailer brake system keeps coming up on my dash. I know a lot of other people have had the same issue keeps dinging will not stop causes me to get distracted while driving. Unable to use other features because of this distraction and safety issue. The safety issue needs to be fixed this is an effective product with so many people having an issue you need to do a recall. I did let Graff Chevrolet in Mount Pleasant Michigan no and I took a picture and showed them.

NHTSA complaint #11748158 — an unverified report by a vehicle owner.

ELECTRICAL SYSTEM

Issue with the trailer brake system keeps coming up on my dash. I know a lot of other people have had the same issue keeps dinging will not stop causes me to get distracted while driving. Unable to use other features because of this distraction and safety issue. The safety issue needs to be fixed this is an effective product with so many people having an issue you need to do a recall. I did let Graff Chevrolet in Mount Pleasant Michigan no and I took a picture and showed them.

NHTSA complaint #11748158 — an unverified report by a vehicle owner.

SERVICE BRAKES

Issue with the trailer brake system keeps coming up on my dash. I know a lot of other people have had the same issue keeps dinging will not stop causes me to get distracted while driving. Unable to use other features because of this distraction and safety issue. The safety issue needs to be fixed this is an effective product with so many people having an issue you need to do a recall. I did let Graff Chevrolet in Mount Pleasant Michigan no and I took a picture and showed them.

NHTSA complaint #11748158 — an unverified report by a vehicle owner.

POWER TRAIN

The contact owns a 2020 GMC Yukon. The contact stated that while depressing the accelerator pedal, there was an abnormal popping sound coming from the engine compartment, and the vehicle hesitated while accelerating. The cause of the failure was not yet determined. The manufacturer was notified of the failure, but no assistance was provided. The local dealer had not yet contacted. The failure mileage was 44,000.

NHTSA complaint #11747108 — an unverified report by a vehicle owner.

UNKNOWN OR OTHER

My vehicle torque converter repair on my 2020 GMC Yukon is shuddering. Why is this not a recall when there are various Yukons that are experiencing shuddering related to torque converter repair. This should be a recall. The problem has been confirmed by a GMC dealer. There were not warning lamps, no messages, or other symptoms.

NHTSA complaint #11739919 — an unverified report by a vehicle owner.

ENGINE

I took my vehicle to a dealer to repair something unrelated to the engine. They said the oil pan was leaking and pulled the pan to discover the crank shaft bearings were failing. The vehicle has 53,765 miles at this point. This appears to be the same defect being recalled on the 2022 through 2024 models.

NHTSA complaint #11737199 — an unverified report by a vehicle owner.

POWER TRAIN

Severe transmission shuttering destroyed my transmission and I need a new one according to a local body shop and a GMC service center. This is a KNOWN issue with these 10 speed transmissions, but they will not recall the ones from this year, they only recalled newer models. Car has been inspected by a local autobody shop, a 3rd party warranty company, and a GMC dealership service center. Shuddering causes severe shaking while driving between 25-65mph. No lights or other symptoms, just started occurring randomly. Purchased car Feb 2025, brought it in to local auto shop November 2025 and they could not get a transmission for months. They stated one was set to be delivered by GMC Feb 6th 2026 and they day before arrival GMC called them saying it was back on back order. Called the dealership in April 2026 and they stated they were not backordered. Had vehicle transferred to dealership service center and they say it’s still on national back order with no ETA. I have been waiting for over 6 MONTHS for a new transmission. This car has been undrivable for almost longer than I have been actually able to drive it.

NHTSA complaint #11737164 — an unverified report by a vehicle owner.

POWER TRAIN

The 2020 Yukon started to have serious loss of speed and decelerating issue when the vehicle would slow down and down shift to a lower gear. The issue with this is that once it downshifted it woul not engage in a gear again and leave me stranded on the road. I had to turn off the car and restart it for it to reengage in a gear enough to get it moving again and sometimes I had to try more than once to get it moving once it no longer wanted to engage in a gear. So in the 10 mile drive, I was left stranded at least 15 times. Each time I had to restart and restart again for the vehicle to engage in a lower gear. Once moving, it would sometimes it would engage in a higher gear and sometimes it would not. Thank goodness I wasn't traveling on the highway when this happened. Beware to anyone if this was to happen on the highway while in the middle lane while in traffic. And the check engine light never turned on and thus no code to help detect the issue. Took it the day before to have it looked at and was told nothing was wrong with it since there was a code and they could not duplicate the issue I described. WHAT?? They reset some transmission computer setting but it only made it worse by the next day. Now this 6 yr on 2020 GM Yukon is at the dealership service department requiring a new transmission for $7200. Said that the transmission fluid was showing particles of stuff and color was 'burnt', I think. Transmission fluid was changed at it's regular check up time so that didn't cause the issue and nor should it have bits and pieces in it and discolored. Is there any recourse to GM and it's crappy transmissions??

NHTSA complaint #11724975 — an unverified report by a vehicle owner.

ENGINE

The 2020 Yukon started to have serious loss of speed and decelerating issue when the vehicle would slow down and down shift to a lower gear. The issue with this is that once it downshifted it woul not engage in a gear again and leave me stranded on the road. I had to turn off the car and restart it for it to reengage in a gear enough to get it moving again and sometimes I had to try more than once to get it moving once it no longer wanted to engage in a gear. So in the 10 mile drive, I was left stranded at least 15 times. Each time I had to restart and restart again for the vehicle to engage in a lower gear. Once moving, it would sometimes it would engage in a higher gear and sometimes it would not. Thank goodness I wasn't traveling on the highway when this happened. Beware to anyone if this was to happen on the highway while in the middle lane while in traffic. And the check engine light never turned on and thus no code to help detect the issue. Took it the day before to have it looked at and was told nothing was wrong with it since there was a code and they could not duplicate the issue I described. WHAT?? They reset some transmission computer setting but it only made it worse by the next day. Now this 6 yr on 2020 GM Yukon is at the dealership service department requiring a new transmission for $7200. Said that the transmission fluid was showing particles of stuff and color was 'burnt', I think. Transmission fluid was changed at it's regular check up time so that didn't cause the issue and nor should it have bits and pieces in it and discolored. Is there any recourse to GM and it's crappy transmissions??

NHTSA complaint #11724975 — an unverified report by a vehicle owner.

ENGINE

TRANSMISSIONS ISSUES. Not transitioning/ shifting into gears smoothly or at all. When it does transition/shift it is rough and harsh. When my car transitions to a lower gear then it will not transition back up to a higher gear causing my vehicle to drop speed significantly that I am a safety hazard on the road. Example: when it shifts to a gear high enough that the vehicle can reach 40 mph and there is a need to decelerate it does but once it drop to lower gears it cannot engage again to a higher gear leaving me stuck going at most 10 mph with not opportunity to excelerate in traffic to a higher speed. The transmission control module (TCM) software was updated with no improvement.

NHTSA complaint #11722542 — an unverified report by a vehicle owner.

SERVICE BRAKES

I had an incident in my 2020 GMC Yukon, where the forward collision crash alert went off and there was total loss of brakes. The brake pedal went to the floor. After the crash alert ended, the brakes returned. This happened on the highway and could have turned into a disastrous event. The dealership has been unable to diagnose or recreate this issue. They claim they did not find anything and the vehicle is safe to drive. I have turned off the collision detection system in the meantime. I feel strongly that this is a software issue that needs addressed. GM has replied that they support the dealership but if I want a second opinion I can go to another dealership for input.

NHTSA complaint #11721207 — an unverified report by a vehicle owner.

FORWARD COLLISION AVOIDANCE: WARNINGS

I had an incident in my 2020 GMC Yukon, where the forward collision crash alert went off and there was total loss of brakes. The brake pedal went to the floor. After the crash alert ended, the brakes returned. This happened on the highway and could have turned into a disastrous event. The dealership has been unable to diagnose or recreate this issue. They claim they did not find anything and the vehicle is safe to drive. I have turned off the collision detection system in the meantime. I feel strongly that this is a software issue that needs addressed. GM has replied that they support the dealership but if I want a second opinion I can go to another dealership for input.

NHTSA complaint #11721207 — an unverified report by a vehicle owner.

ENGINE

MISFIRE ON #6 CYLINDER. DIAGNOSIS REVEALED THE INTAKE VALVE IS NOT OPENING DUE TO COLLAPSED VALVE LIFTER. No message prior to engine light coming on and car shaking after driving back from the store (speed less than 45 MPH).

NHTSA complaint #11715499 — an unverified report by a vehicle owner.

ENGINE

I purchased my 2020 Yukon Denali on July 8, 2024 from Classic Buick GMC in Painesville, Ohio. The check engine light started going on and off a few months after purchasing the vehicle. When I called a mechanic he stated that I should wait until the light is on and then bring in the vehicle. In early May 2025, I took my vehicle to Mike’s Automotive in Middlefield, Ohio after the check engine light began coming on during extended drives (approximately five hours or more). The shop ran a diagnostic scan and advised that the oil pump needed to be replaced. Seeking another opinion, on May 14, 2025, I brought my vehicle to Classic Buick GMC Service, the dealership where I purchased my GMC Yukon. After diagnosing the vehicle, they advised that the check engine light was related to an Engine Oil Pressure Control Solenoid stuck in the off position (P06DD). This fix would cost $3,584. This fix would require the oil pump to be replaced as indicated by the previous repair shop. On May 29, 2025, I took the vehicle to Avenue Auto Clinic in Painesville, OH, where the oil pressure valve and sensors were replaced. The mechanic also advised that I change the oil every 3,000 miles, use OEM oil filters, and thicker oil. He also advised me to check the oil every 1,000 oil and add as needed. I do have to add oil approximately every 1,500 miles and I change the oil every 3,000 miles. I am concerned that my vehicle has the same engine-related defect as the Yukon engines currently under recall. Multiple mechanics have informed me that my vehicle is equipped with the same engine as those affected by the recall. I am requesting that my vehicle be added to the recall. Yes, my vehicle is available for inspection.

NHTSA complaint #11713854 — an unverified report by a vehicle owner.

POWER TRAIN

Transmission started slipping a little and then literally stopped working all with in an hour. And was doa in the parking lot.

NHTSA complaint #11712832 — an unverified report by a vehicle owner.

ENGINE AND ENGINE COOLING

The contact owns a 2020 GMC Yukon. The contact stated that while driving at an undisclosed speed, the check engine warning light was illuminated. The vehicle was taken to the residence, the contact exited the vehicle and discovered white smoke coming from the exhaust and started to smell coolant and then discovered that the coolant level was low. The contact added coolant, and the check engine warning light was no longer illuminated. The contact’s husband and son, who were knowledgeable about vehicles, had self-diagnosed the vehicle and determined that the head gasket or the lifters might need to be replaced. The contact stated that the failure had occurred on several occasions and the contact consistently added coolant; however, the check engine warning light was illuminated every 300 miles once again. The contact researched and was made aware of an unknown NHTSA Campaign Number; however, the VIN was not included. The vehicle was taken to an independent mechanic, where it was diagnosed and determined that there was an unknown internal issue with the engine that was possibly associated with coolant leaking into the engine. The vehicle was not repaired. The manufacturer was not notified of the failure. The failure mileage was approximately 52,000.

NHTSA complaint #11709635 — an unverified report by a vehicle owner.

ENGINE

I purchased a new 2020 GMC Yukon in May of 2020. Between May 2020 and November 2025 the vehicle was routinely serviced on or before the due date recommend by the manufacturer. I had not experienced issues with the vehicle until November 2020 when the check engine light abruptly appeared and the vehicle began driving very rough. I immediately took the vehicle to the local mechanic who identified two codes (P0300 and P050D) related to the engine issues. The vehicle was towed to the dealership due to the fact that I was instructed it was unsafe to drive long distances without additional diagnostics. The dealership disassembled the engine and found coolant leaking into cylinder six. There were no cracks or otherwise clear means of entry for the coolant into the engine. The dealership instructed us that we would need a complete engine replacement. Upon further research of this issue, it was uncovered that a Service Bulletin had been issued for this very issue. The reference number is 20-NA-166, updated March 2024.

NHTSA complaint #11701391 — an unverified report by a vehicle owner.

ENGINE

total engine failure with 90,000 miles on the car.

NHTSA complaint #11700163 — an unverified report by a vehicle owner.

ENGINE

We purchased the vehicle used in April 2025 with 79,851 miles. All service records were documented via Carfax. Vehicle was in impeccable condition. We drove it for approx. 8,000 miles until July 10, 2025, when a loud knocking sound started coming from the engine - approx. mileage 87,600. We drove the vehicle home 350 miles. The knocking sound continued and got slightly worse. We drove it to the nearest dealer (30 miles) and the mechanic said it sounded like a camshaft problem. However, they could not get it in for over 60 days. We drove to another dealer (45 miles). The mechanic said he thought the entire engine was bad. We left the vehicle there and about a week later they were able to confirm that it was TOTAL BEARING FAILURE. Mileage 88,054. We were told that a new engine was needed as well as a radiator and new oil lines, etc. Total estimate $18,000. They also said there was no timeline they could guarantee because of the current GM recall. Of particular note and concern...at no time did the 'check engine' light come on or any other warning system activate. Both mechanics were genuinely perplexed at this. The repairs were ordered and the vehicle is now repaired. However, GM has not confirmed a cost share for the repair billing and we are now almost 60 days since they received the paperwork from the dealer so we still do not have our vehicle back. We filed a complaint with GM and a case number was assigned so they are fully aware of the issue as is the dealer who did the repair.

NHTSA complaint #11697440 — an unverified report by a vehicle owner.

UNKNOWN OR OTHER

My vehicle went from driving perfectly to startling and not going pass 45 in a matter of two days. I was getting all maintenance done at dealer always on time had just service it. When all of a sudden it started making a jerking/ skipping feel as if I was accelerating too hard. Took it to get checked and the code that came up was (TCC)torque converter clutch. I spent 6000 to rebuild the transmission and kno the engine has a tap tap noise. Once again I took it in and now it’s the lifters in the engine. No warning light have ever popped up

NHTSA complaint #11691372 — an unverified report by a vehicle owner.

ENGINE

My vehicle went from driving perfectly to startling and not going pass 45 in a matter of two days. I was getting all maintenance done at dealer always on time had just service it. When all of a sudden it started making a jerking/ skipping feel as if I was accelerating too hard. Took it to get checked and the code that came up was (TCC)torque converter clutch. I spent 6000 to rebuild the transmission and kno the engine has a tap tap noise. Once again I took it in and now it’s the lifters in the engine. No warning light have ever popped up

NHTSA complaint #11691372 — an unverified report by a vehicle owner.

ENGINE

While driving to Lake Placid, NY, I experienced sudden loss of propulsion as I was driving approximately 60 mph. I was able to brake and pull over to the shoulder. I was not able to restart the vehicle - engine was dead. We were flat bed towed to a garage in Lake Placid where it was confirmed that the engine was inoperable. The vehicle is now at. GM dealer in Potsdam, NY. I believe this engine should be part of the recall!!

NHTSA complaint #11672140 — an unverified report by a vehicle owner.