The 2025 GMC Sierra 1500 is positioned as a powerful, feature-rich full-size pickup designed for work and daily driving. Despite its popularity, numerous owners report persistent problems affecting reliability and safety. This article details common complaints backed by National Highway Traffic Safety Administration (NHTSA) data, consumer experiences, and Lemberg Law’s internal data. Our aim is to help vehicle owners that may fall under the lemon law.
Owners and experts have identified several recurring problems in the 2025 GMC Sierra 1500. The top five issues, ranked by frequency and severity, include:
Engine Failure and Seizure: Multiple reports describe catastrophic engine failures, often requiring complete engine replacement.
Transmission Malfunctions: Problems such as rough shifting, sudden loss of acceleration, and uncommanded gear shifts are commonly reported.
Electrical and Infotainment System Failures: Owners have experienced issues with backup cameras, audio system malfunctions, and wireless charging failures.
Brake System Problems: Some vehicles report brake failure or unresponsive braking during critical moments.
Unsafe Vehicle Behavior: Instances of the vehicle shifting gears without driver command or accelerating unexpectedly have caused serious safety concerns.
Additional defects include structural component failures like cracked interior grab handles and concerns over Diesel Exhaust Fluid (DEF) system warnings on diesel models. Below, the top three problems are examined in more detail.
2025 GMC Sierra 1500 Complaint Summary
Complaint Category
Number of Complaints
Electrical System
11
11
Engine
11
11
Power Train
8
8
Unknown Or Other
6
6
Fuel/propulsion System
5
5
Structure:body
3
3
Back Over Prevention: Warnings
2
2
Exterior Lighting
2
2
Service Brakes
2
2
Vehicle Speed Control
2
2
Top Problem #1: Engine Failures and Unexpected Stalling
One of the most alarming issues facing 2025 GMC Sierra 1500 owners is sudden engine failure, including complete engine seizure. This problem has affected both the 6.2L V8 engine and the 3.0L diesel engine
Owner-reported symptoms include:
Sudden loss of engine power with no warning lights
Engine stalls leading to unsafe shutdowns on the road
Engine seizing requiring costly replacement
Persistent oil leaks and cracked valve covers
Warning lights and error codes related to engine and fuel system
Many owners express frustration over delays in dealership diagnosis and repair, often citing long wait times for parts and lack of loaner vehicles during repairs.
Here’s what one owner reported:
“The engine seized and locked up leading to a catastrophic failure of my three month old 2025 GMC Sierra Denali at approximately 3,181 miles. The engine, the 6.2L V8, was listed as a recall engine by GM for model years 2021-2024. My 2025 allegedly “passed inspection” yet had the same catastrophic failure. The vehicle engine made loud noises and it sounded like parts were breaking. The vehicle no longer starts and had to be taken via flatbed to the dealership where I was informed the engine had to be replaced.”
Don’t be stuck with a lemon. You have legal rights to cash, return or buyback.
The law makes GMC pay legal fees.
We've fixed thousands of lemon problems. Message or call 877-795-3666 today.
Top Problem #2: Transmission Malfunctions and Unintended Gear Changes
Transmission issues rank as the second most reported problem for the 2025 Sierra 1500. Complaints include harsh shifts, failure to engage the correct gear, and sudden loss of power.
Owner-reported symptoms include:
Harsh gear shifts occurring unexpectedly at highway speeds
Intermittent or complete loss of acceleration—commonly described as “limp mode”
Vehicle unintentionally shifting from Park to Reverse or Drive
Difficulties with brake response linked to transmission malfunctions
Dealerships often unable to recreate or diagnose the problem fully
One consumer reported, “Truck was in “Park” idling for 20 minutes when it went from Park to “Reverse” on its own. A person sitting in a dump truck saw the backup lights on my truck come on and the truck started backing towards his truck. My truck hit his truck causing damage to my left rear bumper.”
Top Problem #3: Backup Camera and Electrical System Deficiencies
Electrical system defects have affected many owners, compromising both convenience and safety. Failures range from malfunctioning backup cameras to issues with the audio system and wireless charging.
Common symptoms include:
Backup camera image is extremely dark or unusable at night
Audio system power and channel control buttons become unresponsive
Wireless charger pad suddenly stops functioning
Failure of collision warning audios and seatbelt reminders
Cameras shutting down due to overheating of video modules
Lack of dealer resolution despite multiple service visits
Take a look at one owner said about the camera:
“Just purchased a new 2025 GMC Sierra. The backup camera system is useless at night if not in a well lit parking lot. This makes the system unsafe as you cannot detect people or objects in the field of view. I’ve had many GMC vehicles over the years and this is the first one with this concern.”
What Should You Do If Your 2025 GMC Sierra 1500 Is a Lemon?
A vehicle is considered a lemon when it exhibits repeated, substantial defects covered under warranty that impair its use, value, or safety. If your Sierra 1500 has experienced ongoing engine, transmission, or safety-related issues that remain unresolved after multiple repair attempts, you may be entitled to protections under lemon laws.
To protect your rights, take these steps:
Document all repairs, service visits, and communications with dealerships
Keep detailed records of symptoms, warning lights, and safety incidents
File formal complaints with the manufacturer and the National Highway Traffic Safety Administration (NHTSA)
Consult with an attorney experienced in lemon law to evaluate your case
Lemberg Law offers free case evaluations to help Sierra 1500 owners understand their legal options. If your vehicle has repeated problems, you may qualify for a refund, replacement, or cash settlement under state lemon laws.
Think your 2025 GMC Sierra 1500 might be a lemon? Contact Lemberg Law today for a free consultation and explore your legal options.
About the Author:
Sergei Lemberg is an attorney focusing on consumer law, class actions related to automotive issues, and personal injury litigation. With nearly two decades of experience, his areas of practice include Lemon Law (vehicle defects), Debt Collection Harassment, TCPA (illegal robocalls and texts), Fair Credit Reporting Act, Overtime claims, Personal Injury cases, and Class Actions. He has consistently been recognized as the nation's "most active consumer attorney." In 2020, Mr. Lemberg represented Noah Duguid before the United States Supreme Court in the landmark case Duguid v. Facebook. He is also the author of "Defanging Debt Collectors," a guide that empowers consumers to fight back against debt collectors and prevail, as well as "Lemon Law 101: The Laws That Lemon Dealers Don't Want You to Know."
