NHTSA (USA)High Risk
At a glance
What can fail
The front roof panel between the windshield and panoramic sunroof may have been improperly bonded during a prior repair, causing the panel to detach from the vehicle.
This page covers 12 recalls, 98 owner complaints and EPA fuel economy for the 2017 Mercedes-Benz Glc300.
24 mpg combined
9.8 L/100km
Small Sport Utility Vehicle 2WD
Fuel economy data from fueleconomy.gov (EPA / U.S. Dept. of Energy). Annual cost based on 15,000 mi/yr at 55% city driving and current fuel prices. MPG is U.S. gallons; L/100km converted.
Engine and fuel/propulsion complaints dominate the 2017 GLC300 owner reports, with transmission behavior also drawing attention. On the engine side, owners frequently describe stalling, rough running, and unexpected power loss while driving. The fuel and propulsion complaints often overlap with these symptoms, with owners reporting the engine cutting out or hesitating under normal driving conditions. A recurring transmission concern involves the valve body failing, owners describe the vehicle refusing to shift beyond mid-range gears, dropping into neutral unexpectedly while moving, or failing to engage drive at all. Seat belt complaints, though fewer in number, follow a consistent pattern: the latch sticking and requiring multiple attempts before releasing, reported on both front positions. A smaller number of owners mention warning messages related to airbag malfunction appearing on the instrument cluster alongside collision assist system alerts.
98
Total Complaints
3
Crash-Related
2
Fire-Related
2
With Injuries
By System
The 2017 Mercedes-Benz GLC300 has 12 recalls, the most serious involving a starter component that can overheat and melt surrounding parts, creating a fire risk, and a driver airbag that can deploy without warning.
A third fire-adjacent structural concern involves the front roof panel, which may not be properly bonded and can detach while driving, becoming a hazard for other vehicles. A related recall notes that a prior repair attempt on this panel bonding issue may not have fully resolved the problem. On the panoramic sunroof, the front and side plastic panels can also separate during driving and pose a similar hazard to following traffic. The rear outboard seatbelt latch plates can retract into the door panel trim, leaving rear passengers unable to buckle up. Front seatbelt pretensioners may also fail to tighten properly in a crash, reducing how well the front occupants are held in their seats. The electric power steering assist can cut out due to a faulty connection in the control unit, making the steering noticeably heavier and harder to control. Headlights on some vehicles point too low and fail to adequately light the road ahead. Two recalls cover the emergency call system, which can either fail to connect or report the wrong location to emergency services after a crash.
At a glance
What can fail
The front roof panel between the windshield and panoramic sunroof may have been improperly bonded during a prior repair, causing the panel to detach from the vehicle.
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Complaints are owner-reported and reflect individual experiences, not confirmed defects. They are distinct from recalls. Data sourced from the national vehicle safety complaint database. See trending complaints →
What the fix does
Dealers will replace the front roof panel at no charge to you.
Summarized — see the official notice for exact wording, dates, and contacts.
At a glance
What can fail
The front roof panel between the windshield and panoramic sunroof may not be properly bonded to the vehicle from a previous repair, risking separation.
What the fix does
The dealer will remove and replace the front roof panel using proper bonding materials and procedures at no cost.
Summarized — see the official notice for exact wording, dates, and contacts.
At a glance
What can fail
The communication module may have been turned off during service, disabling the Emergency Call function that connects your vehicle to emergency services.
What the fix does
Dealers will inspect the communication module and reactivate it if needed, at no cost to you.
Summarized — see the official notice for exact wording, dates, and contacts.
At a glance
What can fail
The communication module software may fail to send your vehicle's correct location to emergency services when the eCall system activates during a crash.
What the fix does
A dealer will update the communication module software, or the update will be sent over-the-air, at no cost.
Summarized — see the official notice for exact wording, dates, and contacts.
At a glance
What can fail
The seat belt latch plates on the outboard rear seats may retract into the interior paneling, making the seat belts unusable.
What the fix does
Dealers will install felt strips between the C-pillar and rear side paneling to prevent the latch plates from retracting.
Summarized — see the official notice for exact wording, dates, and contacts.
At a glance
What can fail
The seat belt latch plates on the outboard rear seats may retract into the interior paneling, making the seat belts unusable.
What the fix does
Dealers will install a buffer to the c-pillar paneling to prevent the latch plates from retracting.
Summarized — see the official notice for exact wording, dates, and contacts.
At a glance
What can fail
The low beam headlights may be misadjusted, causing insufficient illumination of the roadway ahead.
What the fix does
Dealers will inspect the headlamp adjustment and adjust it as needed at no cost.
Summarized — see the official notice for exact wording, dates, and contacts.
At a glance
What can fail
The plastic panels on the panoramic sunroof may not be bonded securely enough, which could cause them to separate while driving.
What the fix does
Dealers will inspect the sunroof panel bonding and correct it as needed at no cost.
Summarized — see the official notice for exact wording, dates, and contacts.
At a glance
What can fail
The driver's airbag may deploy unexpectedly if the steering components lack proper grounding and the airbag clockspring is broken, allowing electrostatic discharge to trigger deployment.
What the fix does
Dealers will add grounding to the steering components to prevent electrostatic discharge from triggering the airbag.
Summarized — see the official notice for exact wording, dates, and contacts.
At a glance
What can fail
The electrical power steering control unit has improperly welded contact pins that can cause the steering system to malfunction.
What the fix does
Dealers will replace the electric power steering rack at no cost to you.
Summarized — see the official notice for exact wording, dates, and contacts.
At a glance
What can fail
The front seat seatbelt pretensioners may not work properly during a crash, reducing protection for front occupants.
What the fix does
Dealers will replace the front seat belts at no cost to you.
Summarized — see the official notice for exact wording, dates, and contacts.
At a glance
What can fail
When the engine or transmission won't start, the starter motor keeps trying to turn over. This repeated effort can cause the starting current limiter to overheat.
What the fix does
A dealer will install an additional fuse in the electrical line to the starter motor to protect against overheating.
Summarized — see the official notice for exact wording, dates, and contacts.