2020 GMC SIERRA 3500 Complaints

The contact owns a 2020 GMC Sierra 3500 equipped with Goodyear Tires, Tire Line: Wrangler Trail Runner, Tire Size: LT275/65/R20), DOT Number: (NA). The contact stated that while driving approximately 40-45 MPH, the vehicle exhibited the death wobble, causing the vehicle to become difficult to steer. The contact took the vehicle to the dealer to have the wheels aligned; however, the contact was informed of tread separation on the front driver’s side tire, and that the driver’s side rear tire had bubbles. The contact was informed that the passenger’s side front and rear had bubbles as well. The tires were replaced with a different brand tire. The manufacturer was not made aware of the failure. The approximate failure mileage was 29,400.

Rear window leaking on 2020 gmc truck due to faulty rear window seal and plastic slide. Known issue in 2020 models with a service bulletin already in place. Headliner saturated and black mold showing. Rear back liner has been saturated multiple times and gmc would not refund the cost of a whole new window to be put in and reimbursed. GM bulletin # is 18-NA-383

Goodyear Wrangler Trailrunner AT, LT275/65R20, factory installed on a 2020 GMC Sierra Denali 3500. While traveling 60 mph pulling a fifth wheel in South Texas on a clear and dry day, the rear passenger tire unexpectedly lost its tread. As we slowed down, it completely lost tire pressure and we ran on the rim until coming to a complete stop. Immediately prior to the incident, the TPMS and other safety systems in the truck read normal. There were no system warnings and no objects in the road. It put us in a dangerous situation as we were stopped on the shoulder of the highway right before a bridge and had our 3 children in the backseat. We called the police, but they never sent anyone to help with traffic. The rear fender and the wheel well of the truck were badly damaged. We have the faulty tire and it is available for inspection.

I had a blow out on my rear tire on my 2020 GMC Sierra 3500 AT4 truck while travelling down the highway while pulling my 43 foot RV fifth wheel toy hauler. The vehicle had 21,000 miles on it. The tires and wheels are Goodyear Wrangler LT275/65R20 E rated tires. The problem is i changed the tire to find i had a a MICHEllin LT 275/70R18 tire for a spare that i changed. This effected the ABS and was hard pulling my RV back home for another 40 miles. Under NHTSA Campaign number 21V578000 GM recall number N212329780 there was an issue with the spare tire in the sierra 1500 and 2500 trucks but not mentioned in the 3500. This was a huge safety issue for us to pull the truck home as we had to drive at 35 mph for 40 miles on the highway. GM should not be putting a smaller tire/wheel as a spare on a large truck. One side is significanlty lower than the other when the two different tires are on the back of the vehicle.

The exhaust system is directed to the rear of the vehicle and when towing causes extreme heat to build on the item being towed, in my case a 5th wheel camper. The heat has melted the trim on my camper and is a potential fire hazard.

These tires are Good Year Wrangler Trail Runner AT size LT275/65 R20. My total mileage on these tires was 42,751. These were the original tires that were installed when the truck was purchased new. My Tires are rotated every 7,500 miles. Tire pressure is maintained at the exact pressure and in this case was just checked 4 days prior to the incident. I was driving on an interstate at 70 mph. A vibration started. I checked the Tire pressure monitors and all showed normal pressures. About 4 minutes later the vibration increased and I decided to pull over. I had slowed to about 45 mph and had my turn signal On, as I was intending to pull on to the right shoulder. Suddenly the left rear tire exploded, and tread had separated. My truck was damaged . All the components in the wheel well are gone or damaged. The left rear 1/4 panel/fender is bent. NO repair estimate yet. After the incident I saw zero pressure on that tire indicating on the TPMS.

The component that failed was the passenger side or main battery. Our safety was compromised when the design of the HVAC system and the battery location allowed the hydrogen sulfide gas into the passenger compartment of the vehicle. The issue has not been confirmed by a deal or independent service center. The battery(s) and vehicle are available for inspection to confirm the issue. I have uploaded pictures of the battery and one can visually see the swollen battery with liquid leaking out of it. There were no warning messages or other symptoms prior to the failure. The rotten egg smell started shortly after the truck was started and my three young children were in the truck for about 10-15 minutes while I was loading items in the bed of the truck. When I entered the vehicle, the smell was extremely strong and my eyes started burning. I opened all the windows to air out the passenger compartment and thought it was possible off gassing from the nearby septic field. Once driving with the windows now closed, the smell came back instantly and very strong. My children started complaining of headache and nausea. For the next part of the trip, we drove with the windows down. When we arrived at our destination, I was able to determine the smell was coming out of the HVAC system while in normal "Auto" mode. Opening the hood, I went to smell around the engine compartment and when I got over the passenger side main battery, the rotten egg smell was so strong that my nose and eyes instantly started burning. We then drove the truck home with the windows closed and the HVAC system in recirculate but the smell still entered the passenger compartment. All four of us had symptoms of hydrogen sulfide poisoning with my son being the worse with multiple vomiting episodes immediately upon exiting the vehicle. Poison Control was notified and all four of us were evaluated in our local Emergency Department for Inhalation Toxin. The truck is all OEM.

In short, the Diesel Exhaust Fluid (DEF) reductant heater failed which requires the entire DEF tank assembly (part 85138746) to be replaced on my 2020 GMC Sierra 3500. This cause the truck to go into "limp" mode where it will not travel above 65 mph, and after another period, the speed continues to be reduced down to 25 mph. Prior to the speed being reduced, there is a warning message that appears stating "Service DEF System See Owner's Manual" and a warning light illuminates in the gauge cluster. Any severe reduction in speed that can cause the truck to go "limp" is a safety concern. In addition to being a safety concern, some quick internet research reveals that this has been a known problem with GM's DEF system since at least 2019. The electrical connections are too small for the current which supplied the DEF tank heater, causing the system to short and trigger the truck into limp mode which renders it useless. The replacement part is on national backorder, and it has been on backorder for years. My truck is completely useless until this part (or a better-engineered replacement) arrives at the dealer, and there are hundreds if not thousands of people waiting on this same, defective part to get their trucks back on the road. People are losing their livelihood and the means by which they support their families. GM has known about this defective part for years and has done nothing- neither engineered a better part nor issued a recall with some kind of workaround. They haven't even been able to stock the defective part, and this is not just a supply chain issue as new trucks are still being built. This problem was not inspected by any police or insurance agency as it did not cause an accident or injury in this case.

Infotainment system AND center instrument cluster went completely black - six times over the course of one month. I took the truck to Alan Webb Chevrolet in Vancouver Washington. Their service technician was aware of infotainment system “Black Screen of Death - BSD” problems due to previous repair work on several different GM models. However, on the way to their Service Department to get this fixed, I rolled down the driver’s side window about 6 inches to get some fresh air and rolled it back up. Out of nowhere the Infotainment system AND the center instrument cluster came back to life. No rhyme, no reason and both stayed on (illuminated). Their Service Technician could NOT recreate the BSD. They had my truck for more than one week AND said they were working with GM engineers to resolve this issue. GM case number SR 9-7065134382. I’m driving and towing my 5th wheel blind without a remedy for this electrical issue.

The computer lights up the dash reducing power and turning off power to trailer brakes. This has almost caused an accident on several occasions . It happens a couple of times per trips. This vehicle has been in the shop a couple of times per month since it was put into service. Glenn Polk Chevrolet has worked on it each time and the problem is still there. This truck has also had several injector issues. There is an open case with this vehicle with General Motors with no resolution. I have filled out forms on each of my 2020 GMC's 3500's.