Mercedes-Benz · Known Issues
2020 Mercedes-Benz GLA Problems: 15 Known Issues
2020 model year · 2,400+ owner reports · Updated September 2026
2020 · All trims · All engines
Choose the year and equipment for your written issues and visual request.
2020 model year · 2,400+ owner reports · Updated September 2026
2020 · 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 2,400+ owner reports, the 2020 Mercedes-Benz GLA has 15 documented known issues, with 6 rated critical. The most serious are Water Pump Failure ($400-$1,200 repair), 7G-DCT (724.0) Dual-Clutch Transmission Shudder & Mechatronics Failure ($250-$3,200 repair), Diesel EGR/DPF Clogging & AdBlue (SCR) System Faults (OM651/OM654) ($300-$2,500 repair), Steering Shaft Universal Joint Bearing Separation / 'Power Steering Malfunction' Warning ($0-$2,500 repair), Variable Oil Pump Control Solenoid (Y130) Failure Inside Oil Pan - P06DA00 ($700-$2,200 repair) and M270/M274 Timing Chain Stretch & Tensioner Wear (Cold-Start Rattle) ($1,200-$3,000 repair). The most commonly reported issue is Turbo Coolant Line Leak with 1,100 owner reports. Across all issues with published estimates, repair costs range from $120 to $3,200. DIY maintenance guides at au7o.io.
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According to Au7o's analysis of 2,400+ owner reports, the 2020 Mercedes-Benz GLA has 15 documented issues. The most frequently reported are: Water Pump Failure, 7G-DCT (724.0) Dual-Clutch Transmission Shudder & Mechatronics Failure, Diesel EGR/DPF Clogging & AdBlue (SCR) System Faults (OM651/OM654). Of these, 6 are rated critical and should be addressed promptly.
The 2020 Mercedes-Benz GLA has 15 known issues documented across 2,400+ owner reports. 6 issues are rated critical: Water Pump Failure and 7G-DCT (724.0) Dual-Clutch Transmission Shudder & Mechatronics Failure and Diesel EGR/DPF Clogging & AdBlue (SCR) System Faults (OM651/OM654) and Steering Shaft Universal Joint Bearing Separation / 'Power Steering Malfunction' Warning and Variable Oil Pump Control Solenoid (Y130) Failure Inside Oil Pan - P06DA00 and M270/M274 Timing Chain Stretch & Tensioner Wear (Cold-Start Rattle). 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 GLA issues range from $0 to $3,200, depending on the specific problem and whether you choose DIY or professional repair. The most critical issue, Water Pump Failure, typically costs $400-$1,200 to repair. Au7o provides step-by-step DIY maintenance guides that can help reduce repair costs.
The electric water pump on the M270 engine fails, causing loss of coolant circulation and rapid overheating. The pump motor or impeller breaks, and failure is often sudden with no warning. Common between 50,000-90,000 miles. Repairs typically run $400-$1,200. Severity: high.
The X156 GLA's 7G-DCT 7-speed wet dual-clutch transmission (type 724.0) is prone to low-speed shudder/judder, jerky or delayed engagement, and clutch slip, typically emerging from ~40,000-75,000 mi (60,000-120,000 km). Root causes are wet multi-plate clutch wear, degraded/contami… Repairs typically run $250-$3,200. Severity: high.
GLA diesels (GLA 200d/220d), popular in Germany and the EU, develop clogged EGR valves and diesel particulate filters from soot buildup, plus AdBlue/SCR (NOx reduction) faults. EGR carbon fouling causes rough idle, reduced power and emissions faults; DPF blockage triggers limp mo… Repairs typically run $300-$2,500. Severity: high.
Two distinct steering faults recur on the X156. First, a safety recall covers 2017-2018 GLA250 and AMG GLA45 (with 2017 CLA250/B250e and 2017-2018 AMG CLA45): the bore hole in the steering shaft for the universal joint bearing allows excessive movement, and over time the bearing… Repairs typically run $0-$2,500. Severity: high.
The M270 uses a two-stage variable-displacement oil pump whose output is switched by a PWM solenoid (Y130) mounted inside the oil pan, with its wiring harness routed through the pan and out an oil-tight connector. The solenoid winding fails open, or the in-pan harness insulation… Repairs typically run $700-$2,200. Severity: high.
The GLA's M270/M274 turbo four-cylinder petrol engines are widely documented to suffer timing chain elongation and tensioner/guide wear, usually presenting between roughly 40,000-80,000 mi. A loose chain produces a distinctive rattle for the first few seconds after a cold start u… Repairs typically run $1,200-$3,000. Severity: high.
The turbo coolant lines on the M270 engine develop leaks at the quick-connect fittings, causing coolant loss and potential overheating. The plastic connectors become brittle from heat cycling and crack. Repairs typically run $150-$600. Severity: medium.
The 4MATIC transfer case on the GLA develops a whining or humming noise at highway speeds. The noise is caused by gear wear inside the power take-off unit that distributes torque to the rear axle. More common on vehicles that have seen off-road use or aggressive driving. Repairs typically run $200-$2,000. Severity: medium.
GLA infotainment units suffer black/frozen screens and spontaneous reboots. On H247 cars this is the NVIDIA-Tegra-based MBUX head unit, which can fail to boot or reboot ~50 seconds after startup, disabling the rearview camera image (the basis of NHTSA recall 21V354 covering 2019-… Repairs typically run $0-$1,500. Severity: medium.
Mercedes communications directly support discharged 12V starter batteries and no-start conditions on both GLA generations. Communications 10157073, 10157076, 10158199 and 10158370 cover discharged batteries, no-start complaints and excessive quiescent current on earlier GLA vehic… Severity: medium.
On 4MATIC GLA250/GLA220d cars the rear differential carrier assembly is a documented weak point, producing whine, growl, or clunk from the rear (especially on/off throttle and cornering), often at surprisingly low mileage (~50,000-70,000 mi). The differential uses a very small fl… Repairs typically run $150-$2,500. Severity: medium.
GLA owners report the panoramic glass roof spontaneously cracking or shattering, the subject of class-action litigation against Mercedes over allegedly weak/stress-prone panoramic glass. Separately, Mercedes recalled certain 2014-2020 GLA (and other) vehicles because the fixed fr… Repairs typically run $0-$1,500. Severity: medium.
The GLA's panoramic roof drains water through four small tubes that run down the A- and C-pillars. Pollen, grit and - in documented GLA cases - a broken plastic bracket from the sunroof track itself block the tube or the drain channel, so water backs up over the channel lip and r… Repairs typically run $120-$1,500. Severity: medium.
The positive crankcase ventilation regulator is integrated into the plastic valve cover / breather assembly on the M270 and M274 2.0T engines (and carries over in modified form on the M260). The rubber diaphragm inside the partial-load crankcase ventilation valve hardens and tear… Repairs typically run $150-$2,000. Severity: medium.
The GLA hides its reversing camera behind a motorized flap in the tailgate handle trim, which is supposed to swing open when reverse is selected and close again to keep the lens clean. The small flap motor, its position sensor, and especially the flex wiring running into the movi… Repairs typically run $150-$900. 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.