2020 Chevrolet Silverado 1500: stuck in gear or won't shift

Filed Nov 5, 2026 · Transmission · OH

The truck has a serious transmission issue where it either will not shift into gear or gets stuck in a gear. I’ve had several instances on the freeway in traffic where this happens and I’m unable to keep up with the flow of traffic and feared another vehicle would not be able to avoid a collision. I need to exit the freeway and turn the car off for it to reset. But it will often just do this failure again. It creates a very dangerous situation. GM is aware of this, and offered a special warranty repair, but for some reason they refuse to honor the warranty for my truck

Filed Sep 14, 2026 · Electrical, Transmission · TX

rear axle locks up and transmission goes into limp mode , this happens when slow speed under acceleration, this happens almost any time in traffic , at stop light , acceleration to freeway. a safety issue, shows a p0700 code and p2729 code , engine service code light goes on , T/C and skid lights. also happen at hard brakes in traffic lights or fast slow downs

Filed Aug 19, 2026 · Fuel system, Transmission · CA

While driving at highway speed, my vehicle developed a serious transmission problem. At approximately 75 mph, it suddenly lost the ability to maintain speed and dropped to about 55 mph despite throttle input. Engine RPM increased significantly and the vehicle had greatly reduced propulsion. Normal operation temporarily returned after the vehicle was shut off and restarted. The vehicle has also experienced harsh shifting, vibration, limp-mode behavior, a check-engine light, and I reported a momentary wheel-lock event. These symptoms create a safety concern because an unexpected loss of propulsion or abnormal transmission behavior at freeway speeds can increase the risk of a collision. The vehicle was inspected by an authorized Chevrolet dealer. The dealer documented transmission-related diagnostic codes including P0700, P0970, P0968, and P0711. The dealer's repair order specifically referenced GM program N242454441-03, described transmission control-valve wear and pressure loss, and recommended replacement of the valve body. A separate repair estimate included the valve-body assembly and related transmission service parts. Despite the dealer recommending valve-body replacement, GM/dealer coverage was denied primarily because P0747 was not present at the time of diagnosis. I am reporting this because I am concerned that transmission control-valve/valve-body deterioration may cause harsh shifting, reduced propulsion, limp mode, or other safety-related symptoms before or without P0747 being stored. I am asking the federal safety agency to review whether vehicles with the same underlying valve-body failure may remain on the road because the specific qualifying diagnostic code is not present during a dealer scan. The vehicle and transmission are available for further inspection if requested.

Filed May 12, 2026 · Brakes · 114,264 miles · NM

The contact owns a 2020 Chevrolet Silverado1500. The contact stated that while operating the vehicle, four different warning lights illuminated: ABS, Service Brake Assist, Service ESC, and two specific "Brake System Failure" messages limiting the top speed to 42 MPH and 62 MPH, suddenly the vehicle went into limp mode and had to be towed. The vehicle will be taken to a dealer. The vehicle was not repaired. The manufacturer was notified of the failure. The failure mileage was 114,264.

Filed Feb 24, 2026 · Electrical, Transmission · AK

During an extreme cold event in Interior Alaska (–44°F), the vehicle experienced a sudden emissions‑system failure that triggered an EPA‑mandated Limp Mode, limiting the vehicle to 5 MPH on high‑speed highways. This created an immediate life‑safety hazard because it was impossible to maintain a safe speed or exit the roadway due to snow berms. Prior to the failure, the vehicle displayed “Service Emission System” warnings and multiple DTCs related to the reductant heaters and sensors. A dealership technician later confirmed a “burnt pin” at the reductant pump connector, consistent with thermal‑electrical overload. This failure mode matches GM’s TSB 21‑NA‑006, describing connector overheating in cold climates. After the repair, the vehicle continued to exhibit safety‑critical symptoms, including harsh downshifts, delayed engagement, and jerking during deceleration, consistent with Recall 26V083000 (rear‑wheel lock‑up risk). The vehicle also continues to emit an electrical burning odor in cold temperatures, consistent with Recall N192206310 (block‑heater fire risk). The only GM dealership in the region issued a “Termination of Business Relationship,” preventing access to all recall and warranty repairs. This has created a 321‑mile “Service Desert,” making it impossible to obtain federally mandated recall remedies. The vehicle remains unsafe to operate due to unresolved transmission, electrical, and propulsion issues.

Filed Jan 21, 2026 · Transmission · TX

Vehicle was brought to Payne Chevrolet(Weslaco,Tx)for Recall N242454440. After the software update, the vehicle entered 'Limp Mode' and threw a Permanent Fault Code P2817 (Solenoid 8 Stuck Off). The dealership and GM Executive Resolution (Case #86918646) have confirmed this is a mechanical failure of the valve body, but are refusing/delaying the remedy due to a branded title. The vehicle is currently grounded and unsafe to drive as it risks rear-wheel lockup. GM has failed to provide a timely remedy or alternative safe transportation.

Filed Jan 12, 2026 · Electrical, Engine · 29,354 miles · AK

The contact owns a 2020 Chevrolet Silverado 1500. While operating in negative (-41°F) degree winter conditions, the "Service Emission System" entered an EPA-mandated speed limitation in LIMP Mode messages were displayed. Dealer diagnostics confirmed DTC: P20B9 (Heater Control Circuit Open) and P20C1. The failure was identified as the melting of the Diesel Exhaust Fluid (DEF) tank electrical connector due to undersized terminal pins overheating (Joule heating). The contact stated that it was a latent design defect that posed a fire risk and a safety hazard due to sudden loss of motive power in arctic climates (-45°F). General Motors acknowledged the defect in 2500HD models, Special Coverage: N212342980; but excluded the 1500 models. The failure mileage was 29,354.

Filed Jan 12, 2026 · Electrical, Engine · AK

What happened: In mid-December 2025, my 2020 Silverado 1500 (VIN: [XXX] ) suffered a catastrophic failure of the DEF Tank Assembly (P/N 84914535) at 29,354 miles—less than 30% of its warranted life. This is a latent design defect involving undersized terminal pins that suffer thermal degradation and melt the connector during high-amperage heater operation in arctic conditions (Ref: GM TSB 21-NA-006). Component Availability: The failed assembly is held at the dealership. I have submitted a "Part Preservation Request" to ensure it is available for forensic inspection by federal regulators. Safety Risk: The failure triggers an EPA-mandated "Limp Mode," initiating a software-forced reduction in speed. Unexpectedly losing speed on high-speed, icy Alaskan highways—where roadside snowbanks prevent safe egress—creates an extreme risk of rear-end collisions. Furthermore, a vehicle restricted to 5 MPH or rendered inoperable in temperatures of -30°F to -50°F poses a direct, life-threatening risk of cold-weather exposure in remote areas. Confirmation: Failure was confirmed by Lithia Chevrolet GMC of Fairbanks on Jan 7, 2026. GDS2 diagnostic verified DTCs P20B9, P20C1, P205D, and P204C. Data was reviewed by the GM District Manager of Aftersales (DMA) and GM Customer Assistance (Case #[XXX]). Warning Symptoms: Check Engine lamp and "Service Emission System" message appeared in mid-Dec 2025, followed by a "Speed Limited" countdown. The electrical disconnect was abrupt due to terminal pin melting, as documented in my forensic engineering report. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Filed Dec 3, 2025 · Transmission · NY

THIS IS A RECALL REMEDY FAILURE REPORT UNDER 49 U.S.C. §30120. My 2020 Chevrolet Silverado 1500 (VIN: [XXX] ) received Recall 24V797000 on June 9, 2025. The ECM update is intended to detect incipient clutch-pressure or gear-ratio deviations—early signs of a developing slip—and automatically force limp mode to prevent rear-wheel lockup. On August 23, 2025, after the recall was performed, the truck experienced rear-wheel lockup at highway speed. Limp mode did not activate, which shows the recall remedy failed to operate as required. Mangino Chevrolet documented symptoms matching the recall defect, including abnormal ratio behavior. No metal debris was found in the pan, indicating the failure was not caused by wear. GM TAC also noted behavior consistent with a developing slip. GM first recommended full transmission replacement at my expense before acknowledging the recall. GM later authorized a valve-body replacement, which also failed. The dealership owner provided a written statement confirming that: (1) the recall remedy did not correct the defect, and (2) the valve-body repair did not correct it. On December 3, 2025, GM Customer Assistance attempted to close my case as “not recall-related,” despite the post-remedy lockup, limp-mode failure, dealer findings, and the written admission that the recall remedy was ineffective. The safety defect persists after recall completion, and GM has not provided a remedy that corrects it, as required under federal law. I am reporting this as a failed recall remedy and an ongoing safety defect. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Filed Aug 25, 2025 · Transmission · NY

The transmission is locking up at speed causing a significant jump/ lurch in the rear end momentarily that sudden causes lane change. The dealer is telling me this is related to the transmission valve body recall however I received no warning and my truck has never gone into limp mode even though the recall remedy was supposed to provide a 10k mile warning. It would seem the determining factor is not being measured correctly or there are other contributing factors that are not being considered. This seems very dangerous and happened six times over the course of five miles before I could get the truck home and off the road.

Filed Aug 1, 2025 · Electrical, Fuel system · MO

Shop has had the truck over two months and cannot figure out the problem will not go stuck in limp mode.

Filed Jul 5, 2025 · Engine, Transmission · AZ

I was driving and came to a stop at a red light. When accelerating on green the transmission would not go into gear, stalling my vehicle. Nearly causing the vehicle behind me to rear end me. The vehicle eventually went into gear and started to slowly accelerate with shuttering of the transmission.