At a Glance
The Mercedes-benz A-class has 9 identified common problems across 4 generations, with the W168 (1997-2004) being the most affected generation and brakes the most common problem category. Based on 3.3M MOT tests from DVSA data.
Problems are patterns in the DVSA data that occur significantly more often on a specific model than the UK average — confirmed at 99% statistical confidence. Read our DVSA MOT data methodology →
Below: generation-by-generation comparison of Mercedes-benz A-class common problems, MOT failure types, and pass-rate data drawn from DVSA records. Click any generation to see fuel- and engine-specific fault patterns, mileage-banded repair guidance, and the most common MOT failures testers record.
MOT Tests & Failures by Generation
Mercedes-benz A-class generations by MOT tests, failures, and identified problems from DVSA data
Hover over each bar for a full breakdown. Tap any bar to view that generation's problems.
Showing total MOT tests, failures, and known problems per make. Hover over each bar for a full breakdown.
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Browse Mercedes-benz A-class Generations
Select a generation to see its specific problems, MOT failures and advisories
W168
Top issue: Headlamp defect (no aim check)
W169
Most common MOT failure: Windscreen washer not working
W176
Top issue: Airbag warning light on
W177
Most common MOT failure: Tyre condition
Most Common Mercedes-benz A-class MOT Failures
Every reason Mercedes-benz A-class vehicles fail their MOT, ranked by frequency. Select an individual year to see only that year’s failures, or stay on ‘All time’ for the combined picture across our 20 years of DVSA data. Scroll inside the table for the full list.
| # | Failure | % of failures |
|---|---|---|
| 1 | Tyre condition | 10.46% |
| 2 | Coil spring broken or corroded | 7.66% |
| 3 | Tyre tread depth below limit | 7.03% |
| 4 | Stop lamp not working | 6.95% |
| 5 | Brake hydraulic component worn | 6.12% |
| 6 | Number plate lamp not working | 5.38% |
| 7 | Wiper blades deteriorated | 4.94% |
| 8 | Windscreen washer not working | 4.84% |
| 9 | Suspension joint or bush worn | 4.49% |
| 10 | Headlamp aim defect | 4.24% |
| 11 | Brake pads or linings worn | 4.00% |
| 12 | Brake performance below minimum | 2.74% |
| 13 | Shock absorber worn or leaking | 2.56% |
| 14 | Driveshaft fault | 2.43% |
| 15 | Front lamp not working | 1.89% |
| 16 | Indicator fault | 1.88% |
| 17 | Headlamp fault | 1.67% |
| 18 | Airbag warning light on | 1.61% |
| 19 | Rigid brake pipe corroded or damaged | 1.44% |
| 20 | Ball joint dust cover split | 1.27% |
| 21 | Exhaust system fault | 1.25% |
| 22 | Spark ignition emissions above threshold | 1.23% |
| 23 | Brake disc or drum worn | 1.21% |
| 24 | Position lamp not working | 0.93% |
| 25 | Windscreen damage affecting view | 0.89% |
| 26 | Catalytic converter efficiency low | 0.85% |
| 27 | Parking brake performance below minimum | 0.74% |
| 28 | ABS fault | 0.69% |
| 29 | Compression ignition emissions above threshold | 0.61% |
| 30 | Mirror damaged or missing | 0.58% |
| 31 | Horn not working | 0.54% |
| 32 | Seat belt condition | 0.44% |
| 33 | Front suspension joint worn | 0.37% |
| 34 | Rear lamp not working | 0.36% |
| 35 | Tyre pressure monitoring system fault | 0.32% |
| 36 | Flexible brake hose damaged | 0.31% |
| 37 | Parking brake condition | 0.30% |
| 38 | Suspension mounting corroded | 0.26% |
| 39 | Electronic stability control fault | 0.26% |
| 40 | Tyre size or type not matched | 0.25% |
| 41 | Track rod end worn | 0.25% |
| 42 | Fog lamp not working | 0.20% |
| 43 | Bonnet catch or hinge fault | 0.20% |
| 44 | Fuel cap damaged or missing | 0.19% |
| 45 | Subframe corrosion or damage | 0.16% |
| 46 | Steering rack fault | 0.16% |
| 47 | Rear fog lamp not working | 0.16% |
| 48 | Body corrosion or damage | 0.14% |
| 49 | Brake lever fault | 0.13% |
| 50 | Front suspension fault | 0.11% |
| 51 | Wheel bearing worn | 0.11% |
| 52 | Rear suspension fault | 0.09% |
| 53 | Subframe mounting corroded | 0.09% |
| 54 | Bumper damaged or insecure | 0.08% |
| 55 | Handbrake lever fault | 0.08% |
| 56 | Steering column fault | 0.08% |
| 57 | Tyre valve stem damaged | 0.08% |
| 58 | Electrical switch fault | 0.07% |
| 59 | Suspension linkage fault | 0.07% |
| 60 | Chassis condition | 0.06% |
| 61 | Brake pedal fault | 0.06% |
| 62 | Steering free play excessive | 0.06% |
| 63 | Engine mounting worn or broken | 0.05% |
| 64 | Reversing lamp not working | 0.05% |
| 65 | Brake pedal movement restricted | 0.05% |
| 66 | Brake fluid leak | 0.05% |
| 67 | Headlamp levelling device fault | 0.05% |
| 68 | Steering operation fault | 0.05% |
| 69 | Rear reflector damaged or missing | 0.04% |
| 70 | Propshaft fault | 0.04% |
| 71 | Brake caliper fault | 0.04% |
| 72 | Brake fluid level low or contaminated | 0.04% |
| 73 | Dashboard warning lamp fault | 0.04% |
| 74 | Steering coupling worn | 0.04% |
| 75 | Fuel pipe corroded or damaged | 0.03% |
| 76 | Driver airbag fault | 0.03% |
| 77 | MacPherson strut worn | 0.03% |
| 78 | Suspension arm worn or corroded | 0.03% |
| 79 | Undertray damaged or missing | 0.03% |
| 80 | Driver door fault | 0.03% |
| 81 | Steering arm worn | 0.03% |
| 82 | Suspension unit fault | 0.03% |
| 83 | Vehicle structure corrosion | 0.03% |
| 84 | Body security fault | 0.02% |
| 85 | Headlamp washer not working | 0.02% |
| 86 | Electrical wiring fault | 0.02% |
| 87 | Engine oil leak | 0.02% |
| 88 | Fuel tank corroded or leaking | 0.02% |
| 89 | Brake cable, rod, lever or linkage fault | 0.02% |
| 90 | Brake air or vacuum system fault | 0.02% |
| 91 | Drag link end worn | 0.02% |
| 92 | Fuel hose damaged or leaking | 0.02% |
| 93 | Handbrake cable fault | 0.02% |
| 94 | Front passenger door fault | 0.02% |
| 95 | Anti-roll bar worn or corroded | 0.02% |
| 96 | Boot lid damaged or insecure | 0.02% |
| 97 | King pin or swivel pin worn | 0.02% |
| 98 | Brake fluid reservoir fault | 0.01% |
| 99 | Brake fluid warning light on | 0.01% |
| 100 | Electronic braking system fault | 0.01% |
| 101 | Electric power steering fault | 0.01% |
| 102 | Battery loose or leaking | 0.01% |
| 103 | Steering lock fault | 0.01% |
| 104 | Radius arm worn or corroded | 0.01% |
| 105 | Speedometer fault | 0.01% |
| 106 | Steering wheel damaged or insecure | 0.01% |
| 107 | Electronic parking brake fault | 0.01% |
| 108 | Driver seat fault | <0.01% |
| 109 | Bonded suspension condition | <0.01% |
| 110 | Dip switch fault | <0.01% |
| 111 | Spring mounting corroded | <0.01% |
| 112 | Passenger seat fault | <0.01% |
| 113 | Access panel damaged or insecure | <0.01% |
| 114 | Exhaust leak | <0.01% |
| 115 | Tailgate damaged or insecure | <0.01% |
| 116 | Main beam warning light fault | <0.01% |
| 117 | Passenger airbag fault | <0.01% |
| 118 | Mirror or camera fault | <0.01% |
| 119 | Axle beam corroded or cracked | <0.01% |
| 120 | Stub axle worn | <0.01% |
| 121 | Brake back plate corroded or damaged | <0.01% |
| 122 | Window damaged or won't operate | <0.01% |
| 123 | Brake wheel cylinder fault | <0.01% |
| 124 | Steering shaft fault | <0.01% |
| 125 | Power steering pump fault | <0.01% |
| 126 | Power steering pipe or hose leaking | <0.01% |
| 127 | Trailing arm worn or corroded | <0.01% |
| 128 | Seat belt pre-tensioner fault | <0.01% |
| 129 | Hydraulic brake cylinder fault | <0.01% |
| 130 | Semaphore indicator fault | <0.01% |
| 131 | Tie bar or rod worn or corroded | <0.01% |
| 132 | Steering drive system fault | <0.01% |
| 133 | Exhaust emissions above threshold (non-catalyst) | <0.01% |
| 134 | Rear fog lamp warning light fault | <0.01% |
| 135 | Transmission oil leak | <0.01% |
| 136 | Universal joint worn | <0.01% |
| 137 | Daytime running lamp not working | <0.01% |
| 138 | Full power hydraulic brake fault | <0.01% |
| 139 | Additional braking device fault | <0.01% |
| 140 | Indicator warning light fault | <0.01% |
| 141 | Suspension retaining or locking device fault | <0.01% |
| 142 | Axle corroded or damaged | <0.01% |
| 143 | CV joint worn | <0.01% |
| 144 | Seat belt anchorage fault | <0.01% |
| 145 | Hydraulic fluid leak | <0.01% |
| 146 | Reversing lamp switch fault | <0.01% |
| 147 | Brake master cylinder fault | <0.01% |
| 148 | Seat belt or padding damaged | <0.01% |
| 149 | Halfshaft fault | <0.01% |
| 150 | Brake servo fault | <0.01% |
| 151 | Towbar fault | <0.01% |
| 152 | Power steering ram fault | <0.01% |
| 153 | Transmission drive belt fault | <0.01% |
| 154 | Outline marker lamp not working | <0.01% |
| 155 | Wheel hub fault | <0.01% |
| 156 | Exhaust heat shield or sound insulation damaged | <0.01% |
| 157 | Leaf spring broken or corroded | <0.01% |
| 158 | Body strengthening plate corroded | <0.01% |
| 159 | Front fog lamp not working | <0.01% |
| 160 | Spare wheel fault | <0.01% |
| 161 | Passenger compartment corrosion | <0.01% |
| 162 | Vehicle floor corroded | <0.01% |
| 163 | Speed limiter fault | <0.01% |
| 164 | Brake valve fault | <0.01% |
| 165 | Steering box fault | <0.01% |
| 166 | Brake pressure or vacuum buildup insufficient | <0.01% |
| 167 | Suspension linkage attachment bracket or mounting corroded | <0.01% |
| 168 | Hand-operated brake valve condition | <0.01% |
| 169 | Handbrake mechanism or mounting fault | <0.01% |
| 170 | Brake slack adjuster fault | <0.01% |
| 171 | Hazard warning light fault | <0.01% |
| 172 | Loading door damaged or insecure | <0.01% |
| 173 | Steering intermediate drop arm worn | <0.01% |
| 174 | Suspension rod worn or corroded | <0.01% |
| 175 | Dropside damaged or insecure | <0.01% |
| 176 | Steering damper fault | <0.01% |
| 177 | Steering lock stop fault | <0.01% |
| 178 | Brake clevis joint worn | <0.01% |
| 179 | Load sensing valve fault | <0.01% |
| 180 | Seat belt load limiter fault | <0.01% |
| 181 | Hinged tailboard damaged or insecure | <0.01% |
| 182 | Hydraulic suspension accumulator fault | <0.01% |
| 183 | Steering head bearings worn | <0.01% |
| 184 | Air brake cylinder or actuator fault | <0.01% |
| 185 | Anchor bracket corroded | <0.01% |
| 186 | Brake pedal linkage fault | <0.01% |
| 187 | Securing bolts missing or insecure | <0.01% |
| 188 | Spring saddle corroded | <0.01% |
| 189 | Suspension coupling worn | <0.01% |
| 190 | Torsion bar worn or corroded | <0.01% |
Showing all 190 reasons — scroll inside the table for the full list.
Mercedes-benz A-class MOT Failures by Category
Total MOT failure occurrences for the Mercedes-benz A-class, grouped by category. Same data as the failures table above — just sliced by category instead of fault title. Hover a slice for the top failures in each category.
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Frequently Asked Questions
What are the most common Mercedes-benz A-class problems?
Based on analysis of 3.3M Mercedes-benz A-class MOT tests from DVSA data, we have 9 identified common problems across 4 generations. The most frequently flagged issue is "Headlamp defect (no aim check)". Brakes is the most common problem category.
Which Mercedes-benz A-class generation has the most problems?
The Mercedes-benz A-class W168 (1997-2004) (1997–2004) has the highest number of identified common problems (6). Click the generation card above for the full breakdown.
How is this data calculated?
We analyse anonymised DVSA MOT test records under the Open Government Licence. An issue is classified as a "Common Problem" when it occurs significantly more often on a specific model than the UK average, confirmed at 99% statistical confidence. Read the full methodology page for details.
Can I report a problem with my Mercedes-benz A-class?
Yes — use the "Tell Us About Your Problem" form on this page. Your report helps other Mercedes-benz A-class owners spot problems early. All submissions are reviewed before being added to the public database.
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