2019 Mercedes-Benz CLA Reliability Report

The transmission slipping into neutral while driving is the most common complaint, sometimes at 70 mph, with the car coasting until it is restarted. Other reports describe sudden slowdowns from highway speed with a warning on the dash, harsh jerks, rolling backward on hills, and a car that will not shift out of drive. Dealers often cannot reproduce the fault. Two crash reports involve injuries, including a car that moved into reverse and then drive when the owner selected park. One dealer traced a failure to the valve body and low pump pressure.

Knocking, juddering, and front wheels that skip or hop during tight turns show up again and again, often while backing out of parking spaces. Other reports describe the steering wheel locking mid-turn, power steering assist cutting out on the freeway with warning messages, and lane-keeping steering pulling the car toward the median. A front CV axle failed at 36,000 miles. Two crash reports involve hydroplaning in the rain and a locked steering wheel, and one fire-related filing cites hydraulic fluid leaking onto a hot turbo.

Roof glass is the main problem. Panoramic sunroofs crack or shatter at highway speed, and the front roof panel between the windshield and sunroof comes loose as its adhesive breaks down, sometimes flying off on the freeway. Reports put these failures between about 25,600 and 53,000 miles, with one dealer quote above $10,000. Owners also describe wind noise from failed sunroof seals, water leaking into the trunk, and frayed convertible top cables. Most of these filings name the GLC and C300 rather than the CLA.

Factory rims crack or bend without any obvious impact. Owners first notice a slow leak or a tire pressure warning, and a shop then finds cracks on the inner barrel, sometimes on all four wheels. Cracks often come back after repair, and several CLA owners report the problem before 50,000 miles. Replacement quotes run about $1,000 to $1,500 per wheel. Run-flat tires also blow out and cannot be driven even a mile, and with no spare on board, owners end up stranded waiting for a tow.

Airbags fail to deploy in crashes, including side impacts, a deer strike at 50 mph, and a multi-car collision in a CLA250. Four filings involve crashes and five report injuries. Other reports describe the opposite: airbags firing with no impact, at low speed or in heavy rain. Owners also report airbag and SRS warning lights that return after dealer repair, a broken clock spring, and seat belts that lock, stick, or fail to register as fastened. One complaint describes a recall repair delayed because parts were unavailable.

A strong fuel smell inside and outside the car is the top complaint, traced to leaks where the fuel rails meet the injectors. One owner saw fuel burning on the engine after a fuel line leaked at about 76,000 miles. Other reports describe stalling and sudden power loss from failed fuel pumps, a car stuck below 15 mph after a high-pressure pump fault, and a fuel gauge reading wrong. Most of these filings name the C300 and GLA250, plus one A220 with a fuel door that would not open.

Unintended acceleration at very low speed is the dominant pattern. Drivers describe the car surging while parking, pulling into a driveway, or entering a garage, then hitting walls, planters, a garage door, or a parked car. Four of the six filings involve crashes and three report injuries, including head trauma in a CLA250 at about 20,000 miles. Another report describes hesitation when pulling away from a stop that the dealer could not reproduce. One owner complains that Active Brake Assist does not step in while the driver's foot is on the accelerator.