AutoUtility currently tracks 37 official NHTSA owner defect complaints for the 2021 Mercedes-Benz GLS. Electrical System issues are the most frequently reported category, appearing in 17 complaints (45.9% of submitted records). Among these NHTSA complaint records, 2 filings cite a crash, 2 cite a fire, 3 report one or more injuries. The 2021 Mercedes-Benz GLS belongs to the 3rd Generation (X167) platform.

Key Problem Findings
  • Total NHTSA Complaints: 37 reports
  • #1 Reported Problem Area: Electrical System (17 reports • 45.9% of submitted complaints)
  • Secondary Problem Areas: Engine & Cooling (5), Driver Assistance & Safety Tech (5)
  • Crash-Citing Complaints: 2 filings
  • Fire-Citing Complaints: 2 filings
  • Complaints Reporting Injuries / Fatalities: 3 injury filings • 0 fatality filings
Reporting Methodology: Statistics describe unverified consumer submissions voluntarily filed with NHTSA. Complaint volume is not normalized for vehicle sales volume or miles driven. Multiple components can be cited within a single owner complaint submission.
Total Complaints
37
Submitted to NHTSA ODI
Crash-Citing Complaints
2
Filings citing a collision
Fire-Citing Complaints
2
Filings citing smoke or fire
Complaints Reporting Injuries
3
Filings citing one or more injuries
Complaints Reporting Fatalities
0
Consumer filings citing fatalities

Most Reported Problems for 2021 Mercedes-Benz GLS

Top automotive subsystem defect categories ranked by unique owner complaint volume in federal records

#1 Problem Area 45.9% of complaints

Electrical System

17 owner complaints submitted to NHTSA ODI
⚠️ NHTSA Recall Context

NHTSA records list 3 official safety recall campaigns for this model year involving the same broad component area:

*Component overlap means an official recall exists for the same broad vehicle system. It does not establish that an individual owner complaint was caused by, covered by, or resolved through that recall.
🔥 2 fire reports 🩹 1 injury report entry
#2 Problem Area 13.5% of complaints

Engine & Cooling

5 owner complaints submitted to NHTSA ODI
🩹 1 injury report entry
#3 Problem Area 13.5% of complaints

Driver Assistance & Safety Tech

5 owner complaints submitted to NHTSA ODI
⚠️ NHTSA Recall Context

NHTSA records list 1 official safety recall campaign for this model year involving the same broad component area:

*Component overlap means an official recall exists for the same broad vehicle system. It does not establish that an individual owner complaint was caused by, covered by, or resolved through that recall.
✓ 0 crashes or fires cited
#4 Problem Area 5.4% of complaints

Wheels & Tires

2 owner complaints submitted to NHTSA ODI
✓ 0 crashes or fires cited
#5 Problem Area 5.4% of complaints

Fuel & Propulsion System

2 owner complaints submitted to NHTSA ODI
⚠️ NHTSA Recall Context

NHTSA records list 1 official safety recall campaign for this model year involving the same broad component area:

*Component overlap means an official recall exists for the same broad vehicle system. It does not establish that an individual owner complaint was caused by, covered by, or resolved through that recall.
✓ 0 crashes or fires cited
Domain Share Note: Share percentage represents the proportion of unique complaint filings referencing each vehicle system. Because single complaints may cite multiple systems (such as engine and electrical simultaneously), domain percentages represent individual category incidence and may sum to over 100%.

Recent NHTSA Owner Reports for 2021 Mercedes-Benz GLS

Representative defect filings submitted by owners to the NHTSA Office of Defects Investigation

Engine & Cooling NHTSA ODI ID: #11753406
1 Injury Entry Filed: 07/29/2026

"The vehicle suffered a sudden, catastrophic 48V mild-hybrid electrical power supply breakdown and complete system failure while traveling at highway speeds during a cross-country move. The sudden failure forced an emergency lane change into an isolation zone just off the highway. The sudden failure..."

Incident Date: 06/30/2026 • Raw NHTSA Component: ELECTRICAL SYSTEM,ENGINE
Electrical System NHTSA ODI ID: #11730436
Filed: 04/10/2026

"48V battery has repeated failures where I'm driving. safety concern, When it fail, it will pop up warning1) only drive below 50 miles/hour; then it becomes2) stop vehicle immediately; then ) multi-media system suddenly shut off while I'm driving. I tested by 48V battery which only has below 60%..."

Incident Date: 04/10/2026 • Raw NHTSA Component: ELECTRICAL SYSTEM
Fuel & Propulsion System NHTSA ODI ID: #11701200
Filed: 11/24/2025

"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 referred the contact to the..."

Incident Date: 11/16/2025 • Raw NHTSA Component: FUEL SYSTEM, GASOLINE
Wheels & Tires NHTSA ODI ID: #11701188
Filed: 11/24/2025

"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 tires are fine. While you..."

Incident Date: 10/06/2025 • Raw NHTSA Component: WHEELS
Electrical System NHTSA ODI ID: #11661377
Fire Cited Filed: 05/16/2025

"On [XXX], I was heading home from work traveling [XXX] on [XXX] through Atlanta's usual heavy traffic. I smelled smoke inside my car and saw fire flames coming from under my passenger seat. My initial reaction was to try to put the fire out with my hat without burning myself. Also, I had to try to..."

Incident Date: 03/27/2025 • Raw NHTSA Component: ELECTRICAL SYSTEM,SEATS
Consumer Narrative Notice: Excerpts are sanitized text descriptions submitted by vehicle owners to the federal ODI database. They reflect the reporting consumer's observations at the time of filing and have not been independently confirmed by vehicle manufacturers or government investigators.

Complaint History for Mercedes-Benz GLS

Reported defect complaint volume across sibling model years (2017–2026)

Model Year NHTSA Complaints Crash Reports Safety Recalls Detailed Report
2017 Mercedes-Benz GLS 41 1 8 View 2017 Problems →
2018 Mercedes-Benz GLS 22 1 4 View 2018 Problems →
2019 Mercedes-Benz GLS 27 1 3 View 2019 Problems →
2020 Mercedes-Benz GLS 38 3 24 View 2020 Problems →
2021 Mercedes-Benz GLS Current Page 37 2 12 Current
2022 Mercedes-Benz GLS 15 2 10 View 2022 Problems →
2023 Mercedes-Benz GLS 10 0 5 View 2023 Problems →
2024 Mercedes-Benz GLS 0 0 0 View 2024 Problems →
2025 Mercedes-Benz GLS 0 0 0 View 2025 Problems →
2026 Mercedes-Benz GLS 0 0 0 View 2026 Problems →
Comparative Disclaimer: Complaint totals are unadjusted historical counts and are not normalized for vehicles sold, active fleet size, or total road mileage. Newer model years naturally have had less calendar exposure time to accumulate owner filings.

Detailed NHTSA Component Breakdown for 2021 Mercedes-Benz GLS

Complete distribution of consumer defect reports across all 18 granular NHTSA system and subsystem classifications

Vehicle Component / System Total Complaints Crash Reports Fire Reports Reported Injury Entries Reported Fatality Entries
Electrical System NHTSA category: ELECTRICAL SYSTEM 10 0 0 0 0
Other / Uncategorized NHTSA category: UNKNOWN OR OTHER 6 1 0 1 0
ELECTRICAL SYSTEM,ENGINE 2 0 0 1 0
ELECTRICAL SYSTEM,SEATS 2 0 2 0 0
Fuel System NHTSA category: FUEL SYSTEM, GASOLINE 2 0 0 0 0
Lane Departure Warning NHTSA category: LANE DEPARTURE 2 0 0 0 0
Visibility & Wipers NHTSA category: VISIBILITY/WIPER 2 0 0 0 0
Air Bags NHTSA category: AIR BAGS 1 1 0 1 0
ELECTRICAL SYSTEM,UNKNOWN OR OTHER 1 0 0 0 0
ENGINE,FORWARD COLLISION AVOIDANCE,LANE DEPARTURE 1 0 0 0 0
Forward Collision Avoidance NHTSA category: FORWARD COLLISION AVOIDANCE 1 0 0 0 0
POWER TRAIN,ELECTRICAL SYSTEM,ENGINE 1 0 0 0 0
Seat Belts NHTSA category: SEAT BELTS 1 0 0 0 0
SUSPENSION,ELECTRICAL SYSTEM,ENGINE 1 0 0 0 0
Tires NHTSA category: TIRES 1 0 0 0 0
UNKNOWN OR OTHER,STRUCTURE 1 0 0 0 0
VEHICLE SPEED CONTROL,FORWARD COLLISION AVOIDANCE 1 0 0 0 0
Wheels & Hubs NHTSA category: WHEELS 1 0 0 0 0
Data Attribution & Reporting Methodology: Complaints are unverified voluntary submissions to the NHTSA Office of Defects Investigation (ODI). Because multiple vehicle components can be cited within a single owner complaint submission, component-level rollups may sum to more than the unique complaint count (37). Injury and fatality entries in the detailed table reflect raw values entered by reporting consumers across individual submissions; they are not deduplicated casualty statistics and may include duplicate or unverified entries. Complaint volume is not normalized for sales volume or vehicle mileage and does not represent an audited component failure rate.
Official US Government Data Provenance

The complaint records on this page are retrieved directly from the NHTSA Office of Defects Investigation (ODI) public database.

Local Production Store Compiled: August 2026 • Deterministic Audited Dataset • Zero Dynamic External API Runtime Latency.