2020 Mercedes-Benz A-Class Problems: 22 Known Issues

On the 2019-2022 Mercedes-Benz A-Class, the micro-switch inside the W177 driver's door lock uses a housing that does not meet Mercedes' moisture-robustness requirement (a supplier manufacturing deviation). Humidity permeates the plastic housing and corrodes the switch contacts, so the car no longer detects the driver's door opening. Because the electronic parking brake's 'Auto-Park' logic relies on that door-open signal to apply the brake when the driver exits with the transmission in D, a failed switch can leave a vehicle unsecured. Mercedes tracked 176 US field cases between March 2021 and June 2026; owners usually first notice comfort functions misbehaving, most commonly the radio/MBUX staying on after they exit and lock the car, or the interior lights not reacting to the door. NHTSA recall 26V481 covers 310,667 vehicles across the A-Class, CLA, GLA, GLB, C-Class, GLC and CLE (2019-2026).

On the 2019-2020 Mercedes-Benz A-Class, early-production 2019-2020 A220 and A220 4MATIC (along with the 2020 CLA250 and several GLC variants) left the plant with driver's front airbag modules whose retaining bolts may not have been tightened to specification. In a frontal crash the module could shift or detach from the steering wheel during deployment, so the airbag may not protect the driver as designed. NHTSA campaign 19V685 covered 2,222 vehicles in the US; the same defect was addressed by a workshop campaign in other markets. There is no warning before a crash, although a few owners reported a rattle from the steering wheel hub.

On the 2019-2021 Mercedes-Benz A-Class, nHTSA recall 21V-354 covers 2019-2021 A220 and 2020-2021 A35 AMG vehicles whose MBUX display may remain black or reboot, interrupting the rearview image. Recall 22V-232 covers 2019-2020 A220 and 2020 AMG A35 vehicles whose rearview-camera software may fail to display the image within the FMVSS 111 requirement. These are distinct software conditions under the same accurate indexed camera identity.

On the 2019-2020 Mercedes-Benz A-Class, the air conditioning condensate drain hose may not be installed to specification, allowing water to drain into the driver/passenger footwells or center tunnel instead of overboard. Pooled water corrodes and short-circuits electrical control modules in the floor area (SAM, fuel pump control unit, occupancy/SRS sensors). This is NHTSA recall 20V416000 (MB campaign 2020070013), but owners also report wet carpets and module faults outside the recall range.

On the 2020-2023 Mercedes-Benz A-Class M282 1.3L + electric motor (A250e PHEV), the A250e (W177/V177 with the M282 1.3L plus 75 kW electric motor, sold 2020 onward outside North America) has a recurring owner complaint that AC charging stops part-way: the charge cable's status light flashes red, the car shows a 'charging malfunction' message, and the traction battery is left well short of the expected range. A-Class Club members report the fault appearing intermittently at home wallboxes and public posts, cars that will not charge past roughly 80-90%, and dealers replacing the supplied charging cable/ICCB, updating the on-board charger and battery-management software, or in a few cases replacing the on-board charger. Some owners also note the displayed 100% state of charge dropping quickly with light driving. The problem is specific to the plug-in hybrid drivetrain and does not affect the petrol or diesel A-Class.

On the 2019-2023 Mercedes-Benz A-Class, the W177 carries a small auxiliary/backup battery (under the centre console, not in the engine bay) that supports the electronic shifter, start-stop and MBUX during voltage dips. It has a short service life, and when its capacity falls the cluster shows 'Auxiliary battery malfunction' while start-stop stops working. Separately, the main AGM battery on early cars is chronically undercharged: the smart alternator only charges to about 80% in normal driving, and the MBUX head unit, communication module and keyless system draw high standby current, so cars left 3-4 days (or driven only on short trips) go flat or refuse to start. Mercedes issued TSB LI54.10-P-071832 'Vehicle cannot be unlocked / vehicle does not start' with a battery message, LI54.10-P-071499 on Xentry battery-tester disagreements, and multiple MBUX/communication-module software updates to reduce quiescent current. NHTSA complaints on the 2019 A220 include a 738-mile car that would not restart at a fuel station until the battery was disconnected and reconnected.

On the 2019-2022 Mercedes-Benz A-Class, the W177's telematics communication module (HERMES) has been the subject of two US safety recalls plus several service bulletins. Under 21V058 (2016-2021 vehicles) the module's software could report an incorrect vehicle position to the emergency call center after a crash. Under 22V365 (2017-2022 vehicles built Aug 2016-Feb 2022, 1,655 A-Class among roughly 235,000-243,000 total) a security mechanism in the SIM card software could trigger and permanently drop the mobile-network connection, disabling both automatic and manual eCall. Owners see a sporadic 'SOS nonfunctional' message in the instrument cluster (TSB LI82.85-P-076800), wrong clock time (LI82.85-P-071453) and Mercedes me connect services that will not activate or lose remote functions (LI82.85-P-071637, LI8285P073418). The MBUX display bugs already documented in this catalog are a different, head-unit-side problem; this issue is the cellular module.

On the 2019-2025 Mercedes-Benz A-Class, the MBUX infotainment system suffers from frequent software bugs including touchscreen lag, voice assistant failures ("Hey Mercedes" not responding), Bluetooth disconnects, and navigation freezes. The A-Class was the first Mercedes model with MBUX and received early software that was less polished.

On the 2019-2022 Mercedes-Benz A-Class M260 (M260 E20 DEH LA 2.0L turbo), on the M260 2.0L four-cylinder turbo used in the A220, A250 and A35 AMG (and the CLA250, GLA250, GLB250), the exhaust valve seat rings and valve guides can wear prematurely so that the exhaust valves no longer seal. The result is a loss of compression on one or more cylinders, rough idle and misfire codes, and in advanced cases a rattling/ticking top end. Mercedes-Benz USA acknowledged the defect in August 2023 with an Emission Warranty Extension (document MC-10241534-0001, TSB 'ELW-ExhaustValve') covering 2019-2022 A-Class, CLA, GLA and GLB with the M260, extending coverage on the exhaust valve system to 15 years/150,000 miles. Owners on MBWorld and A-Class Club report dealers replacing the complete cylinder head under the extension, and UK A35 owners have documented loss-of-compression diagnoses on the same engine. This is separate from the M282 1.3L intake carbon issue: the M282 is a different (Renault co-developed) engine and does not share this valve-seat defect.

On the 2019-2023 Mercedes-Benz A-Class M282 1.3L turbo, the 1.3L turbocharged direct-injection M282 engine (co-developed with Renault, used in A180/A200) suffers carbon deposit buildup on the intake valves and ports because direct injection does not wash the valve backs with fuel. Deposits build faster on urban/short-trip duty cycles; most engines tolerate them, and rough running and hesitation are noticeable only in rarer cases.

On the 2019-2020 Mercedes-Benz A-Class M260 2.0L (A220), the integral carrier (front subframe component) that supports the front axle can corrode due to a manufacturing defect in which the parts did not receive proper corrosion protection. If the carrier corrodes severely it can fail, which may result in a loss of steering control. This is a NHTSA safety recall (campaign 21V990000) affecting A220 sedans in particular. It is distinct from the routine front strut/suspension noise complaints.

On the 2019-2023 Mercedes-Benz A-Class, the W177's electric power steering column is the subject of a cluster of Mercedes service bulletins: LI46.10-P-077314 'Noises in the steering column area when steering', LI46.10-P-077313 'grinding noises between steering wheel and steering column' (steering column switch module/clock spring contact), LI46.35-P-074816 'squeaking noise from area of input shaft of electric steering', LI46.15-P-070510 'noises from the area of the steering column', and LI46.35-P-075129 'vibrations in steering at speeds lower than 30 mph'. Owners describe a dry rubbing or grinding felt through the rim when turning at parking speeds, a knock when reversing or braking to a stop, and a shudder in the wheel at low speed that dealers first blame on tyres or wheels. A-Class Club threads (including A35/A45 cars on large wheels) confirm the pattern; several owners had the column or switch module replaced under warranty. This is separate from the front-axle carrier corrosion recall and the strut-noise issue already catalogued.

On the 2019-2020 Mercedes-Benz A-Class M260 (M260 E20 DEH LA 2.0L turbo), on certain 2019-2020 A220 and A220 4MATIC (M260 2.0L turbo), a foreign particle could be trapped between the fuel rail and the fuel injector during assembly, damaging the sealing surface. Under high-pressure direct-injection operation the damaged seal lets fuel weep into the engine compartment, where it can reach hot engine or exhaust components. Mercedes filed NHTSA recall 21V961 (MBUSA campaign 2022030003) in December 2021; the whole recall covered only 139 vehicles across many Mercedes models (9 of them 2019-2020 A220s, ~5% estimated defective), and the US recall also included the 2020 AMG A35, CLA250 and GLB250. Owners reported a fuel smell at idle or after parking in a warm garage before any visible drip.

On the 2019-2023 Mercedes-Benz A-Class 2.0L M260 Turbo, the 7G-DCT dual-clutch transmission develops a shudder during low-speed acceleration, similar to driving over rumble strips. The clutch packs overheat in stop-and-go traffic, causing judder and vibration during engagement.

On the 2019-2023 Mercedes-Benz A-Class, on diesel A-Class models (A180d/A200d/A220d, OM608/OM654 engines) driven mainly on short, low-speed urban trips, the DPF cannot reach the high exhaust temperatures needed for passive regeneration. Soot accumulates, the DPF/engine warning light illuminates, and the car can enter limp mode with a stored 'soot content too high' fault. A very common complaint among EU-spec city-driven diesels.

On the 2019-2022 Mercedes-Benz A-Class, two separate headlamp non-compliance recalls hit the W177 in the US. Under 21V509 (2019-2020 A220 and other models) a supplier production deviation put an incorrect data-matrix code (DMC) label on some LED headlamps; on cars whose headlamps were repaired or adjusted using that label, the calibration applied could leave light intensity outside FMVSS 108 limits. Mercedes' remedy was to replace the headlamp units. Under 23V662 (2022 A220, GLA250 and AMG GLA35) the headlights left the factory incorrectly adjusted. On 23V662 cars the practical symptom is a beam aimed slightly too high (glare to oncoming drivers); for 21V509 Mercedes found the deviation affects light intensity at specific measurement points and ruled out any effect perceptible to other road users. Separately, TSB LI82.10-P-064766 covers W177 lamp units fogging or forming droplets, a frequent goodwill/warranty replacement on 2019-2020 cars.

On the 2019-2023 Mercedes-Benz A-Class, the 1.3L M282 engine develops coolant leaks at the integrated thermostat housing/gasket and at the water pump and coolant hoses, commonly in the 55,000-70,000 mile range. A failing thermostat housing causes temperature gauge fluctuation, coolant loss, and slow cabin heating; if ignored it can lead to overheating. Coolant leaks are repeatedly cited as one of the most common cooling-system issues on A 250/A 200 owners.

On the 2019-2023 Mercedes-Benz A-Class, the front MacPherson struts develop a clunking or knocking noise over bumps and rough surfaces. The strut mount bearing wears prematurely, and the strut itself can develop internal valving noise. Mercedes TSB LI32.25-P-070053 attributes thumping over rough roads on cars with standard suspension (SA code 677) to stiff end-stop buffers in the strut support bushing, and cracking or squeaking when steering at low speed to stiff or seized strut plain bearings.

On the 2019-2023 Mercedes-Benz A-Class, the W177's in-cabin temperature sensor sits in the overhead control panel and is ventilated by a tiny aspirator fan. That fan and the fine-wire sensor clog with dust, so the climate control believes the cabin is already cooler than the set temperature and stops requesting cooling: the A/C blows warm or barely cool at 16-18 C while the 'LO' setting (which bypasses the sensor) still produces cold air. Because the compressor and refrigerant charge test fine, dealers have misdiagnosed it as low refrigerant or 'user error'; Mercedes issued TSB LI83.30-P-068662 'Air conditioning system heating instead of cooling' for the A-Class (model 177), naming the overhead control panel temperature sensor as the possible cause, and UK A-Class Club members have posted a step-by-step fix after finding a chunk of dust on the sensor. Some cars needed the sensor/overhead console replaced. This is distinct from the A/C drain-hose water-ingress issue already in the catalog.

On the 2019-2020 Mercedes-Benz A-Class M260 (2.0L turbo), mercedes documents an FSCM software plausibility issue on specified A-Class vehicles. The 2024 US dealer notice lists 2019–2020 A220, A220 4MATIC and AMG A35 4MATIC; model year alone does not establish eligibility. P146264/P146364 may be recorded, but neither code proves the pump or sensor is healthy.

On the 2019-2020 Mercedes-Benz A-Class, 2019-2020 A220 vehicles were delivered without the inspection gauge (and matching owner's-manual instructions) required to check rear brake pad wear, so owners and independent shops had no specified way to determine when the rear pads had reached the wear limit. Mercedes traced the missing gauge to a documentation error in its production control system; the cars have an electronic pad-wear sensor on the front axle, and Mercedes states the front pads always wear out before the rears, triggering a dash warning and a workshop visit at which the rear pads are also inspected. Separately, TSB LI42.15-P-074455 covers front-axle brake squeal when braking to a standstill, and low-speed squeal is widely reported on A35 AMG cars.

On the 2019-2022 Mercedes-Benz A-Class, interior noise is the single most common W177 owner complaint on the UK and US forums, to the point that an A35 owner sold the car after 21 months describing it as 'two cars welded together'. Sources identified by owners and dealers include the central MBUX display housing (Mercedes issued dealer guidelines to add insulating material behind the screen), the hidden owner's-manual compartment in the glovebox, a loose cable under the dash, the triple centre air-vent cluster, rear seat headrest/fold-down catch play, and the panoramic glass roof rubbing on its seals. Mercedes bulletins cover the rear-shelf crossmember noise (LI64.10-P-075514), peeling B-pillar trim seals on the rear doors (LI72.12-P-074542), stiff/noisy door glass (LI72.00-P-076031) and panoramic roof/rollerblind actuation (LI68.69-P-071522). Multiple owners report the dash being removed by the dealer more than once without a full cure.