Heavy-duty trucks carry a reputation for grit, durability, and hard work. The GMC Sierra 2500, especially the 2020 model year and those that followed, was marketed as the truck “made for adventure.”
Adventure took a different turn for many owners when airbags didn’t deploy during collisions, brakes squealed from day one, and steering systems pulled them into dangerous situations. Instead of enjoying the reliability that comes with a workhorse, too many drivers spent their time filing complaints, chasing repairs, or even entering lemon law cases.
The issues with the Sierra 2500 affect safety, drivability, and ownership satisfaction. From faulty roof rail airbags to structural defects that cause hoods to fly open at highway speeds, these are problems that need attention. Hence, understanding the trouble spots, knowing what to watch for, and having the right resources in hand can make all the difference.
Understanding 2020 GMC Sierra 2500 Problems
When we talk about 2020 GMC Sierra 2500 problems, we’re not just pointing to one-off issues. We’re referencing hundreds of consumer complaints logged with the National Highway Traffic Safety Administration, formal investigations into air bag non-deployment, and recalls that cover key systems.
Many drivers deal with electrical glitches, unreliable brakes, and handling quirks that don’t fit the expectations of a $50,000-plus heavy-duty pickup. Taken together, these complaints highlight patterns every current and future owner should know.
● Air Bag Systems That Fail When Needed Most
Airbags are non-negotiable when it comes to modern safety. Yet Sierra 2500 owners faced situations where front or roof rail airbags didn’t deploy in serious accidents. In one documented case, a driver swerved to avoid a stopped vehicle, hit a concrete culvert, and suffered fractured vertebrae because the airbags stayed dormant.
Troubleshooting starts with the basics: if the air bag warning light appears, it’s not a suggestion. It’s a red flag that the SRS system requires immediate diagnosis. A dealership can scan codes, but a Haynes Manual gives owners wiring diagrams and sensor location charts to understand what’s going on beneath the dashboard.
Loose connectors, corroded terminals, or damaged wiring can all trigger system faults. Addressing these problems quickly restores confidence that the system will work when seconds count.
● Brake Problems That Don’t Stay Quiet
Stopping a heavy-duty truck carrying a load or towing a trailer is just as important as making it move. Yet Sierra 2500 drivers repeatedly complain of brakes that squeal from the day they leave the lot.
Brake complaints rank high in the NHTSA database for the 2020 Sierra 2500, with drivers reporting uneven wear, vibrations, and inconsistent stopping power. That’s not what anyone expects from a truck that advertises heavy towing capacity.
Troubleshooting here means checking for pad wear, rotor scoring, and fluid condition. Brake fluid that absorbs moisture loses its efficiency and contributes to a spongy pedal feel. A Haynes Manual covers hydraulic bleeding sequences and torque specifications so owners can replace pads and rotors with confidence. Staying proactive with brake maintenance helps restore quiet operation and also prevents costly damage to calipers and rotors.
● Structural Weakness That Goes Beyond Comfort
Trucks in this class should feel solid, but the Sierra 2500’s record shows weak points that compromise safety and comfort. Seat belt brackets improperly secured at the factory, hoods with striker wires prone to breaking, and even carpeting that can ignite under seat belt pretensioner activation all appeared in NHTSA recall campaigns.
Beyond recalls, drivers note dissatisfaction with interior build quality. Uncomfortable seats paired with questionable fire safety recalls represent more than minor annoyances for a truck used on long job sites or road trips.
The best approach is careful inspection. Hood latch hardware, seat belt mounts, and interior trim should be checked regularly, especially if the truck is used daily. A Haynes Manual provides torque specs and diagrams for these components, giving owners peace of mind that repairs or replacements were done correctly.
● Steering That Doesn’t Stay Straight
Steering problems often feel subtle at first but quickly escalate into safety hazards. Sierra 2500 owners report that their trucks often pull into adjacent lanes within a few hundred feet of travel. Dealers sometimes dismiss this as “within specifications,” but drivers know when a truck becomes unsafe.
The infamous “Chevy Shake” compounds the problem, creating vibrations at highway speeds that undermine driver confidence. With a truck this size, towing or carrying weight only amplifies the issue.
Troubleshooting steering involves more than just wheel alignments. Suspension bushings, tie rods, and tire balance all contribute to straight-line stability. Our Haynes Manual outlines inspection points and acceptable tolerances, making it easier to spot a failing component before it puts the driver and passengers at risk.
● Electrical Failures That Frustrate Owners
Modern trucks rely heavily on electronic modules. Owners of the Sierra 2500 have voiced repeated frustration with infotainment glitches, blank backup camera screens, and even safety systems that fail without warning. Some of these failures prompted class-action lawsuits, with claims that defective in-dash systems left owners stuck with faulty technology.
The starting point is always the fuses and connectors for troubleshooting. From there, wiring diagrams and voltage testing help track down the weak link. Since many safety features like automatic emergency braking rely on the same electrical backbone, catching and correcting these issues early restores functionality to the systems drivers depend on every day.
Wrapping Up: Why Haynes Manuals Are the Best Tool in Your Truck
Owning a 2020–2024 Sierra 2500 means driving a capable heavy-duty truck that also carries a long list of recurring issues. Airbags that don’t deploy, brakes that wear out too quickly, steering that pulls into traffic, and electronics that go dark are not problems anyone wants to face. Yet these are the realities that many Sierra owners have documented.
At Haynes Manuals, we give you the knowledge to troubleshoot problems and keep your truck on the road. Our manuals give you wiring diagrams, torque specifications, and clear diagnostic paths that put control back in your hands.
Our Haynes Sierra 2500 2020–2024 Manual is for the issues you face today. If you’re driving an earlier truck, our 2014–2019 Sierra 2500 & 3500 Manual delivers the same level of guidance.
Gain the insight to handle problems before they sideline your Sierra. Stay ahead and keep your heavy-duty truck working as hard as you do.
