2021 Mercedes-Benz GLS-Class problems
Light NHTSA footprint — 37 owner complaints. Either a clean record or thin data; we'll show what's there.
The 2021 Mercedes-Benz GLS-Class has 37 NHTSA owner complaints on file (U.S. federal records, as of August 2026). The most-reported system is electrical at 15 complaints (~$850 to repair). Source: NHTSA Office of Defects Investigation.
| Model year | Owner complaints | Recalls |
|---|---|---|
| 2018 GLS-Class | 22 | 0 |
| 2019 GLS-Class | 26 | 0 |
| 2020 GLS-Class | 38 | 0 |
| 2021 GLS-Class (this page) | 37 | 0 |
| 2022 GLS-Class | 15 | 0 |
| 2023 GLS-Class | 10 | 0 |
Solid reliability overall. Common issues are concentrated in a few systems.
Buyable on the data — keep up the usual maintenance and inspect normally.
- No systemic severe-failure pattern in the complaint record
- Reliability score 8.2/10 — above the segment average
Our read of the federal NHTSA complaint and recall record for this exact year and model — not a substitute for a pre-purchase inspection. How we score.
Buying a used 2021 Mercedes-Benz GLS-Class? Check these first
Here's what this model is known to do — so you can inspect for it, price it in, or make the seller fix it before you sign.
What to inspect on this specific car
- electrical — 15 owner reports · ~$850 to fix
⚠ The one to take seriously: electrical is flagged severe on this model . Inspect it closely on a test drive.
Recalls to confirm are done
Run the VIN from the listing — no active recalls on this model right now, but confirm none were opened after this car was built.
Verdict for buyers: 8.2/10 model. The priciest documented failure is electrical (~$850) — get the seller's service records for it or inspect closely. Otherwise an average-risk used buy at a fair price.
We tell you what this model is known for and what to inspect — a vehicle-history report tells you what this exact car has been through. Smart buyers get both.
See the full pre-purchase inspection checklist →Ask anything about your 2021 Mercedes-Benz GLS-Class
A noise, a warning light, a repair quote, "should I buy this?" — get an answer grounded in this vehicle's actual NHTSA record, not generic advice.
Answers use this vehicle's NHTSA complaint & recall record — owner-reported and unverified, not a diagnosis. Verify anything safety-critical with a mechanic.
Top trouble spots 1 category with 3+ complaints
What owners are saying recent NHTSA-filed complaints · verbatim
We accepted delivery of our brand new vehicle in May 2021 from the dealer. In July 2021, the vehicle became completely disabled due to failure of the 48 volt battery. In October 2021, the dealer replaced 48 volt battery failed again causing the vehicle to become completely…
The contact owns a 2021 Mercedes Benz GL550. The contact stated that while driving 30 -35 mph an unknown vehicle crossed her path, the driver depressed the brake pedal but was unable to stop before colliding with a vehicle. The steering wheel air bag split open and deployed.…
Both rear wheels on this vehicle have developed cracks which leads to tire pressure loss. Apparently, this is a common issue with Mercedes' heavier vehicles like the GLS and S series sedans. To be clear, I did not hit anything. I did not do any unusual driving. Both rear…
The contact owns a 2021 Mercedes-Benz GLS580. The contact stated that after entering the vehicle, the contact became aware of an abnormally strong fuel odor inside the vehicle. There was no warning light illuminated. The vehicle was taken to two independent mechanics who…
Estimate your repair exposure
Drag to your current mileage. Numbers are derived from this vehicle's complaint history.
Common questions
Is the 2021 Mercedes-Benz GLS-Class reliable?
Mostly yes. With a reliability score of 8.2 out of 10 based on 37 owner complaints filed with NHTSA, the 2021 Mercedes-Benz GLS-Class is generally a sound vehicle. The areas to watch are listed in the top problem section above — most are budget items, not deal-breakers.
Should you avoid the 2021 Mercedes-Benz GLS-Class?
On the NHTSA data, the 2021 Mercedes-Benz GLS-Class does not need avoiding. Buyable on the data — keep up the usual maintenance and inspect normally. The record behind that call: No systemic severe-failure pattern in the complaint record; Reliability score 8.2/10 — above the segment average. This is our read of the federal complaint and recall data — not a substitute for a pre-purchase inspection.
What should I check before buying a used 2021 Mercedes-Benz GLS-Class?
Inspect the electrical first — it's the most-reported issue on this model, with 15 owner complaints filed. Average repair cost runs about $850 at an independent shop. Also confirm any open recalls have been completed by running the VIN, and ask for service records covering the problem areas listed above.
Is the 2021 Mercedes-Benz GLS-Class a good used car to buy?
It scores 8.2 out of 10 on our NHTSA-based read of 37 owner complaints. The main thing to watch is electrical. Priced fairly and clean on inspection, it's a reasonable used buy. Our data covers what this model is known for — pair it with a vehicle-history report on the VIN to see what that specific car has been through.
What's the most common problem on the 2021 Mercedes-Benz GLS-Class?
Based on NHTSA records, the most-reported issue is electrical, with 15 complaints filed. Average repair cost runs about $850 at an independent shop.
What's the most expensive thing that goes wrong?
The electrical is one of the costlier repair items. Average repair cost runs about $850 at an independent shop. Catching early warning signs can sometimes extend life by 20–30,000 miles.
How do I check if my Mercedes-Benz GLS-Class has open recalls?
Paste your VIN into the decoder at the top of this page. We pull live from NHTSA, so you'll see exactly which campaigns apply to your vehicle and whether the dealer has logged the fix. Recall repairs are always free regardless of mileage or warranty status.
Is an extended warranty worth it on a 2021 Mercedes-Benz GLS-Class?
Math is straightforward: a quality service contract runs $1,800–3,500 over 3 years. With 37 complaints on file and the costliest repair averaging $850, one major failure more than pays for it. The catch is reading the contract — many providers exclude wear items and require pre-authorization, so cheaper plans are not always better value.