2020 Chevrolet Silverado 2500: engine overheating

Filed Feb 12, 2026 · Electrical, Fuel system · MD

On approximately January 24, 2026 my 2020 Chevrolet Silverado 2500HD equipped with the 6.6 Duramax Diesel displayed an error code (P20B9). This error code was found to be related to the diesel exhaust fluid system specifically relating to "Reductant Heater A Control Circuit/Open." On January 27, 2026, the vehicle was diagnosed at Chevrolet dealership and the following was reported "Diesel Emissions Fluid Tank Remove and Replace - P20B9 SET FOR REDUCTANT HEATER CIRCUIT...COMMANDED ON AND ZERO AMPS..CIRCUITFAILURE... DISCONNECT PUMP MODULE AND BURNED/OVERHEATED TERMINALS..PUMP MODULE AND HARNESS PART OF TANK ASSEMBLY... LABOR TIME ADDED TO PERFORM MALFUNCTION/TAMPER TEST TO CLEAR EMISSIONS MESSAGE...." I found the "burned/overheated terminals" comment to be alarming. I looked into this matter further and found a GM Service Bulletin (21-NA-006) from October 2022. This bulletin identified this issue which contained an image showing burned/overheated terminals. The identified cause within the bulletin states "This condition may be caused by a poor connection at the Emission Reduction Fluid Tank electrical connector." I believe this should upgraded to a safety recall due the the potential of this terminal connection catching fire which could be detrimental for the operator, passengers, property, and the public.

Filed Feb 12, 2026 · Engine · 173,794 miles · NC

The contact owns a 2020 Chevrolet Silverado 2500. The contact stated that while driving at 50 MPH, the vehicle went into LIMP Mode. The check engine warning light illuminated, and the messages "Service Emission System”, “See Owner's Manual", and "65 MPH Max Speed" were displayed on the instrument panel. The vehicle was taken to the dealer, where it was diagnosed, and determined that the diesel exhaust fluid gas tank connector terminal had overheated, and the gas tank and the wiring harness needed to be replaced. The vehicle was not repaired due to the cost. The vehicle remained at the dealer. The contact associated the failure to the Global Warranty Management: N212342980. The manufacturer was not notified of the failure. The failure mileage was 173,794.

Filed Jan 30, 2026 · Transmission · DE

10L1000 transmission, began having problems with delays and harsh gear engagement. Flare shifting and shuddering. Finally starting having transmission overheating issues while towing. I had to make several unsafe stops with a trailer to wait for the transmission to cool down again before continuing to get it home. Saw trans temps up to 240°F on flat land with 40° outside temps. I could smell the hot transmission fluid inside the truck. When I went to check the fluid level of the transmission, the fluid was full but had a large amount of glitter like metallic flakes. The fluid was very dark brown in color and smelled terribly burnt. The last recall I took in to the dealer for was about the transmissions possibility of failing, locking up, along with the rear wheels at any speed. I have young children that ride in this truck, that in it self was unsettling and unsafe. But then to have issues with absolutely no warning light was concerning. Ive since ordered an aftermarket built transmission to avoid repeating the same issues with a factory GM replacement. My factory warranty had also ended a few months prior to having these problems with it. Leaving me to completely foot the bill for it to be replaced. I had to pull money from my retirement early to cover costs, in fact costing me much more than just the sticker price.

Filed Apr 30, 2025 · Engine · OH

I was driving on Interstate 75 in Ohio when the engine suddenly overheated and completely locked up we were pulling my travel trailer camper at the time which we ended up getting off of an overpass and blocking traffic for several hours until we got the vehicles moved Chevrolet did eventually replace the motor and the entire cooling system with what they claim is a new motor in October of 2024, and within the last couple of days I have noticed a smell coming from the engine compartment that was reminiscent about the smell when it locked up I'm afraid they stuck another motor in my truck that has the same exact issues and once it goes out of warranty I'm going to be stuck with another broke down truck

Filed Jan 24, 2024 · Brakes, Engine · 74,000 miles · CA

The contact owns a 2020 Chevrolet Silverado 2500. The contact stated while driving at an undisclosed speed, the steering wheel briefly became tight before returning to normal functionality. After the failure, the temperature gauge indicated that the engine was overheating. The contact also stated that the brake pedal required excessive force to slow and bring the vehicle to a complete stop. No warning lights were illuminated. The vehicle was taken to an independent mechanic, who diagnosed a failure with the water pump. The vehicle was repaired. The manufacturer was not notified of the failure. The failure mileage was 74,000.