Chevrolet Silverado 3500 won't shift problems

Filed Aug 22, 2026 · OR

Transmission will not shift into high gears throws engine code

Filed Jul 6, 2026 · Transmission · VA

Since buying the vehicle I’ve had issues with the truck going into limp mode with codes p0700 as well as p0747. I have taken it to the dealership twice now, when it has arrived the codes were no longer there. Every time the truck went into limp mode the transmission would get stuck into 5th gear stuck at 45 mph. The problem with the truck started at 48,000 miles, the truck currently has 60,000 miles and the problem has been more active. With the dealership not wanting to resolve the issue the truck was taken to another shop to try to fix the transmission.

Filed Jun 19, 2026 · Acceleration, Engine · OH

My 2026 Chevrolet Silverado 3500 with the 6.6L Duramax diesel has experienced three separate P2463 Diesel Particulate Filter excessive soot accumulation events at approximately 4,300, 5,500, and 10,280 miles. Each event required a Chevrolet dealer to perform a forced regeneration to restore normal operation. The most serious event occurred while towing an approximately 15,000-pound loaded dump trailer on a public county road. While climbing a hill, the truck entered reduced-power/limp mode associated with the emissions/DPF system. Power was reduced so severely that the truck could no longer continue uphill and came to a stop in the travel lane. This created a safety hazard because the road was narrow and winding, with no safe place to pull off. I had to back the truck and loaded trailer several hundred yards downhill while traffic was present behind me. Before the event, the truck displayed “Continue Driving, Cleaning Exhaust Filter.” The warning did not state that severe power reduction or loss of towing capability was imminent. I did continue operating the vehicle, but the truck was being used for normal commercial towing/work operations where immediate highway-speed driving was not practical. The issue has been confirmed by Chevrolet dealers through DTC P2463 on multiple visits. The only correction performed has been forced regeneration. I was advised that no failed component was identified and no permanent repair has been performed. The vehicle is available for inspection, and repair records are available. My concern is that the emissions-related derate strategy can cause sudden and severe loss of motive power while towing on public roads, leaving the vehicle unable to maintain forward movement or safely clear the travel lane. This has occurred repeatedly during normal work use, not as a one-time event, and the warning provided did not give a clear indication that the truck could soon become unable to tow or maintain forward movement.

Filed Feb 20, 2026 · Fuel system · NY

Service engine light kept coming on the dash, and the code came back to a faulty DEF heater. My truck had a reduced power countdown on the dash indicating the truck was going go to into limp mode after x amount of miles. On warmer days the code would go away and there would be no reduced power. The vehicle was diagnosed at a GM dealership and confirmed the DEF heater was bad, but was notified that there is a bulletin with GM for this issue occurring in many other diesel trucks. My safety was put at risk due to the rapidly changing reduced speed milage, at any point it could drop from 100miles, to 10 miles until reduced speed. This could cause an instant car accident while driving if the truck were to randomly slow down to a speed much slower than the speed limit. IE- driving on the north way (65 speed limit) and having the speed drop to 5mph unexpectedly when you just had over 100 miles to reduced speed.

Filed Jan 28, 2026 · Transmission · OK

the federal safety agency Vehicle Safety Complaint I am reporting a serious transmission defect in my 2024 Chevrolet Silverado 3500HD LT that creates a high risk of sudden power loss, erratic shifting, or loss of control while driving. Vehicle Details: - Make/Model/Year: Chevrolet Silverado 3500HD LT, 2024 - VIN: 2GC4YTEYXR1263768 - Engine: 6.6L Duramax diesel - Transmission: 10-speed Allison (10L1000) - Mileage at diagnosis: ~46,000 miles - Title: Rebuilt (warranty denied due to branding) Defect Description: The transmission shifts normally when cold (fluid below ~138°F). Once warm (during normal driving), it fails to upshift properly in gears 5-8: holds lower gears, causes high RPMs (3,000+), delays shifts excessively, or refuses to shift. When shifts occur, they are hard and jerky. Automatic (Drive) mode is affected; manual/L mode works normally as a workaround. No warning lights appeared initially, but the issue has worsened and is now frequent at operating temperature. Diagnosis: On January 28, 2026, Seminole GM (1405 N Milt Phillips, Seminole, OK 74868; 405‑382‑6130) diagnosed a defective valve body requiring replacement. Quote: - Valve Body Control Module (Part #24065357): $687.48 - Transmission Fluid (12 qt @ $10.92): $131.04 - Labor (diagnosis + pan/filter/relearn): $805.50 - Supplies/taxes: ~$140 - Total: $1,763.94 Dealer confirmed this is a common issue; photos of quote available for upload. Safety Risks: At highway speeds, delayed/no upshifts can cause: - Sudden inability to accelerate (merging, passing, hills) - Harsh engagement leading to wheel slip or loss of control - Potential limp mode entry, stranding in low gears This intermittent warm-only failure is unpredictable and dangerous. Context: This matches widespread complaints on 2023-2025 GM HD trucks with the 10L1000 (forums: DuramaxForum, Reddit r/Duramax/r/Silverado, GM-Trucks.com), involving valve body wear/pressure loss. Earlier years had related recalls (e.g., the federal safety agency 24V‑797 for valve issues),

Filed Oct 1, 2025 · Transmission · CO

I was driving on the interstate at around 65mph. Towing my fifth wheel. Transmission started shifting hard with a loud bang that sounded like we hit a huge pothole. A message popped up in the screen indicating “Reduced acceleration, drive with caution”. The transmission seems to be stuck in gear as we exited the highway. Check engine light was on. Came to a stop at a stop sign and barely had enough power to pull into a parking lot. We had the truck towed to a nearby dealership. Fault codes P0700 and P0747 were present. Service advisor said valve body would have to be rebuilt. It’s been 2 weeks and the valve body cover plate is still “backordered” with no estimated in stock date.

Filed Aug 10, 2025 · Transmission · WA

Driving on highway at 40mph while towing a trailer the rear tires briefly locked up, then the Check Engine Light came on and vehicle went into limp mode. Dealer confirmed transmission valve body issue. Same problem as recalled on earlier model year vehicles. Seems like 2023-2025 vehicles should be added to the original recall to ensure support and long-term warranty protection.

Filed Jun 2, 2025 · Transmission · AL

Transmission shifting hard while pulling lawn trailer. Truck goes into limp mode, exhaust brake shuts off, and check engine light comes on P0747. Dealer said bad valve body which could have damaged transmission. No parts in sight. Known GM issue bot my 2023 3500HD is not covered in recall????

Filed Apr 30, 2025 · Transmission · CO

I recieved a recall notice from Chevrolet stating they needed to install a software update to the truck which will warn if a potential rear wheel lock up is about to occur due to faulty transmission valve body- which was stated that they do not have a fix for. After software update was installed- I was driving about 35 mile per hour on the trip home, and the truck abruptly downshifted very hard, momentarily locking up rear wheels, and the check engine light came on, and the vehicle message came up stating the vehicle was placed in a reduced propulsion mode(limp mode). The next day it did it again on my short drive to work of 2 miles. I took into dealership and they informed me that the valve body had failed- as mentioned in the recall notice. It is now 1 month later and I still do not have my truck back, the part is back ordered, and they have no idea when it will be fixed. I am without my primary form of transportation.

Filed Apr 10, 2025 · Transmission · CO

Valve body failure. Truck is 6 months old. Just hit 37000 miles. Engine brake disengaged, check engine light, trailering option disabled, and would not shift out of 1st gear. Towed to dealership to be told valve body failed. Replacement part has been ordered and no eta on availability. Gm might need to buy my truck back!