2016 Mercedes-Benz CLA Problems: 16 Known Issues

On the 2015-2018 Mercedes-Benz CLA, mercedes-Benz AG determined that on certain MY2015-2018 CLA (117 platform) vehicles the calibration of the front-passenger Occupant Classification System might not meet production specification because seat supplier Adient installed some seats with incorrect OCS calibration parameters. A child seat could be classified as an adult occupant (airbag stays ON with a child seat mounted) or a small, light adult could be classified as a child seat (airbag OFF with a person seated). The affected US population is 2015-2018 CLA250 and CLA250 4MATIC and 2017-2018 CLA45 AMG; MB internal recall number 2020060012.

On the 2014-2018 Mercedes-Benz CLA, daimler determined that on 2014-2018 CLA250, CLA250 4MATIC and CLA45 AMG 4MATIC (117 platform, alongside C-, E-, GLA-, GLC-, GLK- and B-Class electric) an electrostatic discharge, combined with a worn/broken steering column module clock spring and insufficient grounding of the steering components, could trigger an inadvertent driver airbag deployment. A broken clock spring first shows up as a driver-airbag warning message and the red SRS lamp. The recall covered 495,290 vehicles across models with an estimated 1% defect rate; MB's investigation traced five field reports of unintended deployment.

On the 2014-2019 Mercedes-Benz CLA, on first-generation (C117, 2014-2019) CLA250 4MATIC and CLA45 AMG cars the electronically coupled rear differential (with its engagement solenoid on the front-left of the housing) wears internally well before 100k miles. Owners describe a whirring/whine that grows with speed, and a clunk, click or pop from the rear when slowing, accelerating or turning from a stop. Dealers diagnose it quickly as the differential; Mercedes supplies the unit only as a remanufactured complete assembly and forum reports put dealer replacement around $6,000, with owners citing failures between roughly 20k and 80k miles. One forum poster relayed a service manager's view that the diff and gearbox were under-engineered for the CLA45's output.

On the 2014-2020 Mercedes-Benz CLA, the 7-speed dual-clutch automatic (7G-DCT, transmission code 724.0) fitted to CLA 200/220/250 models develops a noticeable shudder or jolt during low-speed engagement and when shifting from 2nd to 3rd under moderate throttle. Causes include wet multi-plate clutch wear, degraded/contaminated transmission fluid, and failure of the electronic mechatronics (valve body/TCM) unit that controls clutch pressures and gear engagement. Owners also report hard or delayed engagement when coming to a stop and shifting into P/N/R, plus jerky take-off. The DCT is highly sensitive to fluid condition (MB spec 236.21) and outdated control software.

On the 2014-2019 Mercedes-Benz CLA, mercedes recalls 21V-197 and 23V-854 establish that the bonded front stationary panel on certain 2014-2019 CLA panoramic roofs may not have been installed correctly during prior repair. Bonding adhesion can deteriorate, allowing partial or complete panel detachment and increasing crash or injury risk. The campaigns are VIN-specific and do not establish that every vehicle in the frozen year range is affected.

On the 2014-2019 Mercedes-Benz CLA, first-generation CLA250 owners report the dash message 'Power Steering Malfunction – see Owner's Manual' with the wheel suddenly becoming very heavy, often on cold mornings or right after start. The CLA uses a fully electric rack (no hydraulic fluid) so the fault is electrical: dealers most often replace the complete steering rack/EPS unit, with torque-sensor or steering-angle-sensor faults and low battery voltage as the other findings. Multiple mercedescla.org threads from 2014-2018 cars document the same message, and one owner's fix required the rack under warranty. Weak 12V batteries in cold weather can trigger the warning spuriously, so battery testing is the first check.

On the 2014-2022 Mercedes-Benz CLA, both CLA generations have been recalled three times for the telematics/communication module that places the automatic emergency call. 19V-787 (Nov 2019): on 2014-2016 CLA250, CLA250 4MATIC and CLA45 AMG (117 platform) a supplier software fault caused the module's GPS-derived date/time to drift from Nov 4, 2019, so vehicle position could be delayed or impossible and an inaccurate location sent to the emergency center; 24,226 vehicles remained after OTA updates. 21V-058 (Mar 2021): on MY2016-2021 CLA (and many other lines) the module could report an incorrect location because a temporary voltage drop in a crash disturbed position handling. 22V-365 (May 2022; MB campaigns 2022060005 and 2023110006, letters in phases from July 2022 to September 2024): on 2017-2022 CLA the SIM card software could disable itself, preventing any mobile-network connection so manual and automatic eCall are unavailable.

On the 2014-2019 Mercedes-Benz CLA, c117 CLA owners on MBWorld and mercedescla.org report condensation and standing water inside the headlamp housings, followed by an intermittent or dead low beam and a dead LED daytime running light strip. The housing seal fails, water reaches the ballast/LED control module mounted in the lamp, and the module shorts. Cases include a 2014 CLA250 with right low beam and DRL out and a 2016 CLA45 with a water-killed left headlamp. Mercedes does not sell the seal or module separately in most cases, so out-of-warranty owners face a complete headlamp assembly.

On the 2014-2023 Mercedes-Benz CLA, cLA owners frequently see an 'Auxiliary Battery Malfunction' message on the dash. The CLA uses a small secondary 12V battery to support electronics and the start/stop system; it typically degrades after roughly 4-6 years. A weak auxiliary battery, or a charging fault (alternator/voltage regulator, loose connections), triggers the warning and can cause intermittent electrical glitches in the infotainment, lighting and start/stop function, sometimes with a stored 9062 fault.

On the 2014-2019 Mercedes-Benz CLA, cLA owners report a check engine light with P0128 (coolant temperature below thermostat regulating temperature): the gauge sits low, cabin heat is weak and fuel economy drops because the map-controlled thermostat fails open. On the M270 CLA250 the thermostat sits behind the water pump so labor is significant, and dealers have replaced the thermostat under warranty after a second visit. On the M133 CLA45 the job is worse: a 2018 CLA45 owner was quoted about $3,600 because the dealer booked 9 hours of labor. Related codes P0597 (thermostat heater control) appear alongside P0128 on some cars.

On the 2014-2019 Mercedes-Benz CLA M270, owners of first-generation CLA250s report water pump failure on the M270 2.0T well inside typical service life — one MBWorld reviewer's pump failed at about 36,000 miles, and mercedescla.org threads describe coolant loss, overheating warnings and a pump found leaking at the weep hole. Because the pump is driven off the timing chain side of the engine and shares its housing area with the thermostat, labor dominates the bill: an owner complaint on file records roughly $1,400 with 8 hours of labor.

On the 2014-2019 Mercedes-Benz CLA, the M270 2.0L turbo engine develops oil leaks from the turbo oil feed and return lines. Oil drips onto the hot exhaust manifold, producing smoke and a burning oil smell. The turbo oil return line gasket is the most common leak point.

On the 2014-2023 Mercedes-Benz CLA, cLA owners report rear brake pads and rotors wearing out before the fronts, with early 'Check Brake Pad Wear' warnings (some as low as ~50k miles) and rear rotor warping/vibration. A commonly cited root cause is the rear caliper piston sticking/dragging — a problem owners and independent mechanics say Mercedes is aware of on CLA and C-Class — which keeps the pad in contact with the rotor, accelerating wear and causing noise. Brake squeal from glazed rotors/worn pads is also common.

On the 2014-2023 Mercedes-Benz CLA, cLA owners report water collecting in the trunk and pooling in the rear footwells, sometimes enough to soak carpets and risk corrosion and electrical faults. A common path is poorly sealing rear pressure-relief vent flaps and water tracking down inside the trunk lid around the tail-light cluster, then into the body. Owners also cite weak factory seam sealer on spot-welded roof/rear upper body panels and door seals that let rainwater seep onto sills.

On the 2014-2023 Mercedes-Benz CLA, the front struts and strut mount bearings develop clunking and creaking noises over bumps. The CLA shares its platform with the A-Class and both suffer from the same strut mount bearing wear issue, especially on models with sport suspension.

On the 2014-2019 Mercedes-Benz CLA, a widely repeated C117 complaint: the front seat belt webbing rubs the B-pillar trim as it retracts, fraying and marring the pillar cover, while the plastic belt guide clip rattles against the trim over bumps. Owners on mercedescla.org describe dealers replacing both B-pillar trims and fitting redesigned belt clamps with a stiffer lip, which cures both the chafing and the rattle. It is cosmetic but recurs if the original clip design is reinstalled.