AI Damage2020 Mercedes-Benz GLC 350 reliability: common problems
Owners of the 2020 Mercedes-Benz GLC 350 filed 1 complaints with NHTSA, most often about electrical system and structure. The maker issued 121 service bulletins for this year. Details by component below, with sources.
Key figures
- Owner complaints
- 1
- Technical service bulletins (TSB)
- 121
What fails most often
- 1 Electrical system 100% of all complaints
- 2 Structure 100% of all complaints
- 3 Engine 100% of all complaints
- Electrical system: 1 complaints (100% of all); manufacturer bulletins for this component: 59.
- Structure: 1 complaints (100% of all); manufacturer bulletins for this component: 12.
- Engine: 1 complaints (100% of all); manufacturer bulletins for this component: 2.
Components owners complain about
| Component | Owner complaints | involving a crash | Technical service bulletins (TSB) |
|---|---|---|---|
| Electrical system | 1 | 0 | 59 |
| Structure | 1 | 0 | 12 |
| Engine | 1 | 0 | 2 |
| Equipment | 0 | 0 | 23 |
| Steering | 0 | 0 | 12 |
| Powertrain | 0 | 0 | 10 |
| Exterior lighting | 0 | 0 | 9 |
| Engine and cooling | 0 | 0 | 6 |
| Visibility | 0 | 0 | 6 |
| Fuel system | 0 | 0 | 3 |
| Suspension | 0 | 0 | 3 |
| Backover prevention | 0 | 0 | 2 |
| Communication | 0 | 0 | 2 |
| Fuel/propulsion system | 0 | 0 | 2 |
What owners report
Short excerpts of NHTSA complaints in the original wording. These are owner statements not verified by NHTSA; personal data removed.
Engine coolant after 2000 miles from topped off by dealership got low and sparked fire, and totaled my car. Warning alert was ON to say turn off engine remove key.
Comparison
By complaint count this model year ranks 21,984 of 32,257 model years in the NHTSA data (among the 32% least complained about).
On average one model year of the GLC 350 has 3 complaints (3 years in the data). This year has 1, below average.
What to check before buying
- Electrical system. Scan all modules, test the battery and alternator, inspect connectors near the impact zone.
- Structure. Rails, pillars, panel gaps, signs of pulling or welding.
- Engine. Cold start, unusual noises, oil leaks and engine codes.
- Steering. Steering play, power assist, rack and tie rods after a wheel impact.
Manufacturer service bulletins
Bulletin titles as filed with NHTSA.
- Complaint Clanking noise from the area of the speakers in the doors
Cause Under analysis. Remedy To narrow down the cause, first of all remove the door trim. • If the noise continues to occur even with the door trim removed, then continue the diagnosis working towards the speaker and…
- Complaint Repeat workshop visit for vehicle vibration while braking from 60MPH. NOTE
Although the symptom is similar to a tire or wheel vibration, it is usually readily noticeable that it is distinctly different if it happens at all times or only while braking. Cause Although the cause of the vibration…
- Complaint Mercedes-Benz USA is currently experiencing limited availability of transmission fluid…
Complaint Mercedes-Benz USA is currently experiencing limited availability of transmission fluid specification ATF 236.17 due to a global supply constraint. 236.17 ATF 1L and 5L (PNs: A002989060312 and A002989060313)…
- • Always use the latest XENTRY Diagnosis software release with all available add-ons
• Make sure to follow the operation steps exactly as described in XENTRY Diagnosis! • Use a battery charger to ensure sufficient power supply of the vehicle on-board electrical system battery (greater than 12.5 V). •…
- Single throttle lift-off clunking noise from the side shaft when moving off (audible at the outboard end)
The noise is heard once in each instance when changing direction of travel. Note: Sound file in attachment Cause If the complaint is eliminated by experimentally loosening the outboard collar nut (by 1 turn), the…
- Complaint There are several types of complaint about noises or poor windshield wiper wiping performance
A: Wiper blades squeaking, chattering, shuddering B: The windshield is not wiped completely (streaking) C: During the downward movement water is pulled back onto the windshield from the A-pillar (Figure 1) D: After…
- Complaint Headlamp, front fog lamp leaky or fogged
Cause Fogging of the headlamps is a natural phenomenon, which can occur under certain climatic conditions. It does not lead to any technical impairment of the headlamp. If a pressure compensation diaphragm is fitted in…
- Complaint Check engine light on with the following fault is current in the VGS Control Unit
P084300 Oil pressure sensor 'A' has a short circuit to positive stored in VGS control unit. Cause Electrical failure of oil pressure sensor integrated into VGS Control Unit Remedy Intelligent Predictive Repair (IPR)…
- Complaint 1
General Diagnostic Tips 2. One or More PARK Sensor Activations 3. Red Ring Around Vehicle 4. "Active Parking and Parking Assist Inoperative" on Instrument Cluster 5. Cameras 6. Other Park Topics Cause Various root…
- Complaint Activating Navigation Please Wait" message seen on central display
Cause Under Analysis Remedy 1.Reset the MBUX language (e.g., if the MBUX language is set to English, please change it to any other language and then set it back to English again) 2.If the issue still persists after the…
- Complaint Only vehicles with a variable transfer case are affected
This can be identified through control unit N45 or N15/7 in the quick test. When accelerating with light load, vibrations or jolting sensation may come from the drivetrain. It may be mistaken for a harsh shift. Cause…
- Complaint Traffic sign symbol for "Traffic Sign Assist" is blinking in instrument cluster without obvious…
Complaint Traffic sign symbol for "Traffic Sign Assist" is blinking in instrument cluster without obvious cause usually with one of the following scenarios: • Flashing without a speed limit ("- -"). • Flashing when…
NHTSA lists 121 bulletins for this year; the 12 newest are shown here.
Other years of this model
Questions and answers
What are the most common problems with the 2020 Mercedes-Benz GLC 350?
Owner complaints to NHTSA most often mention: electrical system, structure, engine. Total complaints: 1. The most frequent symptoms in complaint texts: smoke, burning smell, fire (100%).
How many service bulletins (TSB) were issued for the 2020 Mercedes-Benz GLC 350?
NHTSA lists 121 manufacturer service bulletins for this year. A bulletin tells dealers how to diagnose or fix a known issue; it is not a recall.
Should I buy a 2020 Mercedes-Benz GLC 350 from a US auction?
Owner complaints describe defects, not crash damage. Before bidding, check the components listed above and review the lot photos: VinWind builds a report of visible and hidden damage by VIN.
Other 2020 models
Read also
Sources: public NHTSA data (USA): service bulletins and owner complaints; YouTube: links to videos credited to their authors. Complaints are owner statements not verified by NHTSA, and describe defects rather than crash damage. Data updated 2026-11-06.