Mercedes-Benz · Known Issues
2019 Mercedes-Benz GLC Problems: 13 Known Issues
2019 model year · 3,100+ owner reports · Updated September 2026
2019 · All trims · All engines
Choose the year and equipment for your written issues and visual request.
2019 model year · 3,100+ owner reports · Updated September 2026
2019 · All trims · All engines
Choose the year and equipment for your written issues and visual request.
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According to Au7o's analysis of 3,100+ owner reports, the 2019 Mercedes-Benz GLC has 13 documented known issues, with 4 rated critical. The most serious are GLC 350e High-Voltage System Faults and Charging Failures (Plug-In Hybrid Only) ($900-$9,000 repair), SCR / AdBlue System Plausibility Failure Triggering a No-Restart Countdown (OM651 Diesel) ($400-$3,000 repair), Active Brake Assist and 360-Degree Camera False Activations (Phantom Braking) ($0-$1,500 repair) and Diesel Timing Chain Tensioner Seal Oil Leak and Chain Stretch (OM651) ($600-$2,500 repair). The most commonly reported issue is 9G-Tronic Harsh Shifting with 2,000 owner reports. Across all issues with published estimates, repair costs range from $120 to $9,000. DIY maintenance guides at au7o.io.
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According to Au7o's analysis of 3,100+ owner reports, the 2019 Mercedes-Benz GLC has 13 documented issues. The most frequently reported are: GLC 350e High-Voltage System Faults and Charging Failures (Plug-In Hybrid Only), SCR / AdBlue System Plausibility Failure Triggering a No-Restart Countdown (OM651 Diesel), Active Brake Assist and 360-Degree Camera False Activations (Phantom Braking). Of these, 4 are rated critical and should be addressed promptly.
The 2019 Mercedes-Benz GLC has 13 known issues documented across 3,100+ owner reports. 4 issues are rated critical: GLC 350e High-Voltage System Faults and Charging Failures (Plug-In Hybrid Only) and SCR / AdBlue System Plausibility Failure Triggering a No-Restart Countdown (OM651 Diesel) and Active Brake Assist and 360-Degree Camera False Activations (Phantom Braking) and Diesel Timing Chain Tensioner Seal Oil Leak and Chain Stretch (OM651). Prospective buyers should inspect for these issues and factor potential repair costs into their purchase decision. Regular maintenance following the manufacturer's schedule helps prevent many common problems.
Repair costs for known Mercedes-Benz GLC issues range from $0 to $9,000, depending on the specific problem and whether you choose DIY or professional repair. The most critical issue, GLC 350e High-Voltage System Faults and Charging Failures (Plug-In Hybrid Only), typically costs $900-$9,000 to repair. Au7o provides step-by-step DIY maintenance guides that can help reduce repair costs.
The pre-facelift GLC 350e plug-in hybrid has a distinct set of high-voltage complaints that do not apply to the mild-hybrid or conventional GLC 300. Owners report a red battery malfunction telltale with the car refusing to start for several minutes, an amber engine light and the… Repairs typically run $900-$9,000. Severity: high.
European-market GLC 220d and 250d models with the OM651 diesel run an SCR aftertreatment system that will refuse to allow further engine starts once the control unit loses confidence in NOx conversion. Owners and technicians report the dash showing "Engine start not possible in x… Repairs typically run $400-$3,000. Severity: high.
GLC owners report the driver-assistance suite reacting to obstacles that are not there. The "checking surroundings" screen pops up several times a week with sections of the car outlined in red and nothing nearby, and — more seriously — Active Brake Assist has applied the brakes w… Repairs typically run $0-$1,500. Severity: high.
EU-spec GLC 220d/250d diesels with the OM651 engine are prone to a leaking timing chain tensioner sealing ring, which causes oil loss at the chain tensioner and can lead to timing chain stretch and rattle. Mercedes recalled over 100,000 OM651 vehicles in Germany over sealing-ring… Repairs typically run $600-$2,500. Severity: high.
The 9G-Tronic (725.0) nine-speed automatic transmission exhibits harsh downshifts and jerky low-speed behavior, particularly the 1-2 and 2-1 shifts. The transmission software struggles with the many gear ratios at parking lot speeds. Repairs typically run $150-$2,500. Severity: medium.
The integrated PCV / crankcase breather valve in the intake manifold (M274 2.0L turbo) commonly fails or its diaphragm tears, causing unmetered vacuum leaks. Oil mist can then migrate up the engine wiring harness via capillary action, contaminating connectors. Reported predominan… Repairs typically run $320-$2,200. Severity: medium.
On the X253 GLC 300 the vacuum-operated turbo wastegate actuator uses a rubber diaphragm that hardens and tears after repeated heat cycling. Once it splits, the actuator can no longer hold vacuum, the wastegate hangs open, and the engine never builds commanded boost. The ECU logs… Repairs typically run $350-$900. Severity: medium.
GLC headlamp assemblies collect water inside the lens. Mercedes recalled a narrow build window — 129 units of 2021 GLC 300, GLC 300 4MATIC, AMG GLC 43 and AMG GLC 63/63 S built May-June 2021 — because the sealing plugs in the headlamp connector housing were not properly installed… Repairs typically run $0-$2,200. Severity: medium.
X253 GLC owners report a heavy metallic clunk from the front end, most obvious over expansion joints and while turning, along with a squeak from the front suspension at low speed. The cause is the rubber bushings in the front lower spring control arm and the hydraulic (fluid-fill… Repairs typically run $600-$1,800. Severity: medium.
On the M274/M264 2.0L turbo engines used in the GLC, the intake camshaft adjuster relies on an internal locking pin that wears over time. Without oil pressure at cold start, the adjuster fails to lock in its default position, producing a distinct metallic rattle for 2-4 seconds o… Repairs typically run $800-$2,500. Severity: medium.
The panoramic sunroof develops creaking and rattling noises over bumps and temperature changes. The glass panel expands and contracts differently than the metal frame, creating friction-induced squeaks especially in cold weather. Repairs typically run $0-$500. Severity: low.
Early X253 GLCs (2016-2019) are widely reported to squeal from the brakes, especially when backing up or in cold/damp weather, partly due to glazed pads and moisture trapped in drilled rotor holes. Separately, the rear brakes wear out noticeably before the fronts because the Elec… Repairs typically run $200-$600. Severity: low.
The GLC power tailgate uses a motorised spindle drive on one side and a gas-charged support strut on the other. When the gas charge leaks out of the passive strut, the tailgate no longer has enough force to stay up: owners describe the boot opening normally and then immediately c… Repairs typically run $120-$450. Severity: low.
Content on this page was compiled with AI assistance using NHTSA complaints, TSBs, owner reports, and public automotive data. While we strive for accuracy, this information may contain errors. Always verify repair procedures and specifications with your vehicle's service manual or a qualified mechanic.