2021 GMC Sierra 1500

Engine

Engine and cooling problems are among the most serious defects under California’s Song-Beverly Act. Owners of the 2021 GMC Sierra 1500 have reported issues including stalling, overheating, loss of power, rough idling, excessive oil consumption, and check engine lights that return after dealer repairs. With 852 NHTSA complaints on record, this defect pattern is well-documented. Owner reports include: “at roughly 5,000 miles had lifter failure which caused loss of power. That was repaired under warranty. Same issue at 86,000 miles – loss of power. New engine which I had to pay for. Same issue at 126,000 miles. New engine required. Covered under warranty. Side note. New engine will only have balance of warranty from 2nd engine or about 5,000-6,000 miles. first incident Feb 2001, second incident about Nov 2004, third incident Mar 2026.” (NHTSA Complaint #11725006)

Powertrain

Powertrain and transmission defects directly impair the vehicle’s core function and are generally considered substantial defects under California lemon law. Owners of the 2021 GMC Sierra 1500 have reported harsh shifting, shuddering, slipping, and transmission warning lights. 330 NHTSA complaints have been submitted for this defect category. Owner reports include: “The valve body failed, brought it in to a GMC dealership 3 months ago they told me the valve body is on back order. Last week they received the new valve body installed it and tried to program it. While programming it, the brand new valve body failed. So now I am stuck again with no ETA of when a new valve body will be sent to the dealership to fix the issue. this is obviously an issue with the make and model and in my opinion should be a recall. I do not feel safe if I ever get my truck back from this issue due to ongoing valve body failures nation wide and two on my end.” (NHTSA Complaint #11722468)

Engine & Cooling

Engine and cooling problems are among the most serious defects under California’s Song-Beverly Act. Owners of the 2021 GMC Sierra 1500 have reported issues including stalling, overheating, loss of power, rough idling, excessive oil consumption, and check engine lights that return after dealer repairs. With 216 NHTSA complaints on record, this defect pattern is well-documented. Owner reports include: “The contact owns a 2021 GMC Sierra 1500. The contact stated that on Aug. 14, 2025, the PICO engine test was completed on the vehicle under NHTSA Campaign Number: 25V274000 (Engine and Engine Cooling). The dealer stated that the engine had passed the test, and the engine oil was changed to a higher viscosity oil, and the oil cap, oil filter, and the page in the Owner’s Manual were updated. The contact stated that the vehicle was making abnormal sounds while idling, and the fuel consumption had increased. The dealer was contacted and advised the contact to bring the vehicle back to have the engine test performed again; however, the contact refused. The vehicle was not repaired. The contact stated that the engine test had not been performed on the vehicle and that the vehicle was unsafe. The manufacturer was informed of the failure and informed the contact that the vehicle was repaired. The failure mileage was approximately 44,000.” (NHTSA Complaint #11725266)

Power Train,Engine

Engine and cooling problems are among the most serious defects under California’s Song-Beverly Act. Owners of the 2021 GMC Sierra 1500 have reported issues including stalling, overheating, loss of power, rough idling, excessive oil consumption, and check engine lights that return after dealer repairs. With 156 NHTSA complaints on record, this defect pattern is well-documented. Owner reports include: “Driving down the road and engine shut off and would not start back. Had it towed to dealer and it needed a motor replacement. Waited over a month for the shop to finish it. New motor has 3k miles on it and is making noise, transmission is stuttering hard and the air conditioning quit working all around the same time. Had to take the truck back to the dealer after the replacement motor was installed because of a faulty “new” starter.” (NHTSA Complaint #11722817)

Electrical System

Electrical system failures are notoriously difficult to diagnose and repair, which often results in multiple unsuccessful repair attempts — a key element of a lemon law claim. Reported issues for the 2021 GMC Sierra 1500 include infotainment malfunctions, battery drain, warning lights, power window failures, and intermittent starting problems. 156 NHTSA complaints have been filed for this category. Owner reports include: “Truck went in service 9/17/2025 because the wheels locked up while driving. Transmission was replaced. Picked up truck and 2 hours later the truck shut off while driving and was started back up and was limp mode. Was told wire chaffing and they taped and rerouted wires. Picked truck back up and next day it did the same thing. Took back to the dealer and they said wires again. They taped wires back up and we picked up the truck. We had it 7 days and while driving down the expressway the whole truck shut off and would not start up again. Clearly that is a safety issue. After sitting on the side of the expressway for 10 minutes it started up again and was in limp mode and taken to the dealer again. I don’t know what has been done to it yet as they are not great at communication but they have had our truck for 4 months minus the 7 days we had it before it had to go back to the dealer.” (NHTSA Complaint #11711286)

Active NHTSA Recalls — 2021 GMC Sierra 1500

The following 7 recalls have been issued for the 2021 GMC Sierra 1500 by the NHTSA or GMC. If your vehicle is affected, the manufacturer is required to provide a free remedy. Check your VIN at NHTSA.gov/recalls.

California Lemon Law — Song-Beverly Act

California’s Song-Beverly Consumer Warranty Act (Cal. Civ. Code §§ 1790–1795.8) is one of the strongest lemon laws in the United States. It protects buyers and lessees of new and certified pre-owned vehicles that develop substantial defects the manufacturer cannot repair after a reasonable number of attempts.

Under Cal. Civ. Code § 1793.22, a lemon law presumption is triggered when any of the following apply to your 2021 GMC Sierra 1500:

• 4+ repair attempts for the same non-safety defect without resolution
• 2+ repair attempts for a defect likely to cause death or serious bodily injury
• 30+ calendar days out of service for warranty repairs (cumulative, not consecutive)

Once the presumption is triggered, the burden shifts to GMC to prove the vehicle is not a lemon. Under Cal. Civ. Code § 1794(d), GMC must pay your attorney’s fees if you prevail — meaning qualified representation costs you nothing out of pocket.

What You Can Recover

If your 2021 GMC Sierra 1500 qualifies as a lemon under California law, GMC may be legally required to:

• Repurchase your vehicle — Full refund of your down payment, all monthly payments, registration fees, and incidental costs (towing, rentals), minus a mileage offset for miles driven before the first repair attempt
• Replace your vehicle — Provide a new, comparable vehicle at no cost to you
• Pay your attorney’s fees — Under § 1794(d), GMC pays all legal fees if you prevail
• Civil penalty up to 2x damages — If GMC willfully violated the Act, courts may award double the actual damages

Steps to Protect Your 2021 GMC Sierra 1500 Claim

Step 1: Document every repair visit. Keep all repair orders, work orders, and dealer invoices. Each visit counts as a repair attempt, even if the dealer says nothing is wrong.

Step 2: Keep returning for repairs. You must give GMC a reasonable opportunity to fix the defect. Visit different authorized GMC dealers if needed and ask for written documentation of each visit.

Step 3: Contact a California lemon law attorney. Once you believe the threshold has been met — 4 attempts for non-safety defects, 2 for safety defects, or 30 days out of service — contact an attorney for a free case evaluation. Under § 1794(d), GMC pays your fees if you win.

Step 4: Send a demand letter. Your attorney will send GMC a formal demand letter. Most California lemon law cases resolve through negotiation without going to trial.

2021 GMC Sierra 1500 Lemon Law Questions

How many repair attempts qualify my 2021 GMC Sierra 1500 as a lemon?

Under Cal. Civ. Code § 1793.22, four or more repair attempts for the same non-safety defect, or two attempts for a safety-related defect, triggers the lemon law presumption. Additionally, 30 or more cumulative days out of service qualifies regardless of the number of repair attempts.

Does GMC pay my attorney fees?

Yes. Under Cal. Civ. Code § 1794(d), GMC is required to pay your reasonable attorney’s fees and court costs if you prevail in a lemon law claim. This means qualified lemon law representation is free to you if your case succeeds.

Can I file a lemon law claim without an active recall?

Yes. A recall is not required to file a lemon law claim. The Song-Beverly Act covers any substantial defect that impairs the use, value, or safety of the vehicle that the manufacturer cannot repair after a reasonable number of attempts. NHTSA complaints support the claim by establishing a pattern, but are not a prerequisite.

What is the time limit to file a lemon law claim for my 2021 GMC Sierra 1500?

California lemon law claims are generally subject to a four-year statute of limitations from the date you discovered or should have discovered the defect. However, you must still be within the manufacturer’s original warranty period when the defect first appears. Contact an attorney promptly to preserve your rights.