At a Glance
The Mercedes-benz M-class has 26 identified common problems across 3 generations, with the W163 (1997-2005) being the most affected generation and brakes the most common problem category. Based on 874K 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 M-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 M-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 M-class Generations
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Most Common Mercedes-benz M-class MOT Failures
Every reason Mercedes-benz M-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 | Stop lamp not working | 8.60% |
| 2 | Number plate lamp not working | 7.72% |
| 3 | Tyre tread depth below limit | 6.29% |
| 4 | Brake hydraulic component worn | 5.81% |
| 5 | Suspension joint or bush worn | 5.70% |
| 6 | Brake pads or linings worn | 5.38% |
| 7 | Coil spring broken or corroded | 5.38% |
| 8 | Tyre condition | 4.87% |
| 9 | Front lamp not working | 4.44% |
| 10 | Wiper blades deteriorated | 3.57% |
| 11 | Headlamp aim defect | 3.27% |
| 12 | Windscreen washer not working | 2.66% |
| 13 | Brake performance below minimum | 2.60% |
| 14 | Track rod end worn | 2.49% |
| 15 | Position lamp not working | 2.21% |
| 16 | Driveshaft fault | 2.03% |
| 17 | Front suspension joint worn | 2.00% |
| 18 | Rigid brake pipe corroded or damaged | 1.97% |
| 19 | Headlamp fault | 1.84% |
| 20 | Indicator fault | 1.67% |
| 21 | Shock absorber worn or leaking | 1.34% |
| 22 | Steering rack fault | 1.24% |
| 23 | Airbag warning light on | 1.03% |
| 24 | ABS fault | 0.92% |
| 25 | Brake disc or drum worn | 0.91% |
| 26 | Windscreen damage affecting view | 0.89% |
| 27 | Parking brake performance below minimum | 0.86% |
| 28 | Seat belt condition | 0.75% |
| 29 | Compression ignition emissions above threshold | 0.71% |
| 30 | Mirror damaged or missing | 0.70% |
| 31 | Fog lamp not working | 0.67% |
| 32 | Parking brake condition | 0.65% |
| 33 | Horn not working | 0.63% |
| 34 | Rear lamp not working | 0.63% |
| 35 | Exhaust system fault | 0.62% |
| 36 | Catalytic converter efficiency low | 0.54% |
| 37 | Ball joint dust cover split | 0.47% |
| 38 | Spark ignition emissions above threshold | 0.45% |
| 39 | Electronic stability control fault | 0.35% |
| 40 | Rear fog lamp not working | 0.29% |
| 41 | Body corrosion or damage | 0.25% |
| 42 | Flexible brake hose damaged | 0.25% |
| 43 | Engine oil leak | 0.23% |
| 44 | Power steering pipe or hose leaking | 0.22% |
| 45 | Steering free play excessive | 0.20% |
| 46 | Battery loose or leaking | 0.19% |
| 47 | Brake pedal fault | 0.19% |
| 48 | Steering arm worn | 0.17% |
| 49 | Suspension linkage fault | 0.15% |
| 50 | Vehicle structure corrosion | 0.14% |
| 51 | Dashboard warning lamp fault | 0.13% |
| 52 | Tyre size or type not matched | 0.13% |
| 53 | Rear reflector damaged or missing | 0.12% |
| 54 | Handbrake cable fault | 0.11% |
| 55 | Drag link end worn | 0.10% |
| 56 | Front suspension fault | 0.09% |
| 57 | Propshaft fault | 0.09% |
| 58 | Brake fluid leak | 0.09% |
| 59 | Headlamp levelling device fault | 0.09% |
| 60 | Wheel bearing worn | 0.09% |
| 61 | Tyre pressure monitoring system fault | 0.08% |
| 62 | Chassis condition | 0.08% |
| 63 | Brake lever fault | 0.07% |
| 64 | Brake caliper fault | 0.07% |
| 65 | Rear suspension fault | 0.07% |
| 66 | Brake pedal movement restricted | 0.06% |
| 67 | Driver seat fault | 0.06% |
| 68 | Steering column fault | 0.05% |
| 69 | Electrical wiring fault | 0.05% |
| 70 | Bumper damaged or insecure | 0.05% |
| 71 | Suspension mounting corroded | 0.05% |
| 72 | Fuel pipe corroded or damaged | 0.04% |
| 73 | Anti-roll bar worn or corroded | 0.04% |
| 74 | Bonnet catch or hinge fault | 0.04% |
| 75 | Brake fluid level low or contaminated | 0.04% |
| 76 | Subframe corrosion or damage | 0.04% |
| 77 | Tyre valve stem damaged | 0.04% |
| 78 | Brake cable, rod, lever or linkage fault | 0.03% |
| 79 | Exhaust leak | 0.03% |
| 80 | Headlamp washer not working | 0.03% |
| 81 | Power steering pump fault | 0.03% |
| 82 | Fuel tank corroded or leaking | 0.03% |
| 83 | Electrical switch fault | 0.03% |
| 84 | Suspension unit fault | 0.03% |
| 85 | Steering lock fault | 0.03% |
| 86 | Fuel hose damaged or leaking | 0.03% |
| 87 | Fuel cap damaged or missing | 0.03% |
| 88 | Handbrake lever fault | 0.03% |
| 89 | Power steering ram fault | 0.02% |
| 90 | Brake fluid warning light on | 0.02% |
| 91 | Steering operation fault | 0.02% |
| 92 | Boot lid damaged or insecure | 0.02% |
| 93 | Front passenger door fault | 0.02% |
| 94 | Electric power steering fault | 0.02% |
| 95 | Body security fault | 0.02% |
| 96 | Towbar fault | 0.02% |
| 97 | Transmission oil leak | 0.02% |
| 98 | Suspension arm worn or corroded | 0.02% |
| 99 | Electronic braking system fault | 0.02% |
| 100 | Undertray damaged or missing | 0.02% |
| 101 | Brake air or vacuum system fault | 0.01% |
| 102 | Tie bar or rod worn or corroded | 0.01% |
| 103 | Passenger seat fault | 0.01% |
| 104 | Suspension air bellows damaged | 0.01% |
| 105 | Dip switch fault | 0.01% |
| 106 | Rear fog lamp warning light fault | 0.01% |
| 107 | Driver airbag fault | 0.01% |
| 108 | Hydraulic fluid leak | 0.01% |
| 109 | Handbrake fails on gradient | 0.01% |
| 110 | Speedometer fault | 0.01% |
| 111 | King pin or swivel pin worn | 0.01% |
| 112 | Mirror or camera fault | 0.01% |
| 113 | Spare wheel fault | <0.01% |
| 114 | Brake fluid reservoir fault | <0.01% |
| 115 | Tailgate damaged or insecure | <0.01% |
| 116 | Steering wheel damaged or insecure | <0.01% |
| 117 | Suspension linkage attachment bracket or mounting corroded | <0.01% |
| 118 | Electronic parking brake fault | <0.01% |
| 119 | Brake servo fault | <0.01% |
| 120 | Universal joint worn | <0.01% |
| 121 | Reversing lamp not working | <0.01% |
| 122 | MacPherson strut worn | <0.01% |
| 123 | Air suspension levelling valve fault | <0.01% |
| 124 | Passenger airbag fault | <0.01% |
| 125 | Steering drive system fault | <0.01% |
| 126 | Steering box fault | <0.01% |
| 127 | Steering coupling worn | <0.01% |
| 128 | Driver door fault | <0.01% |
| 129 | Steering shaft fault | <0.01% |
| 130 | Subframe mounting corroded | <0.01% |
| 131 | Window damaged or won't operate | <0.01% |
| 132 | Additional braking device fault | <0.01% |
| 133 | Exhaust emissions above threshold (non-catalyst) | <0.01% |
| 134 | Suspension rod worn or corroded | <0.01% |
| 135 | Front fog lamp not working | <0.01% |
| 136 | Hydraulic brake cylinder fault | <0.01% |
| 137 | Main beam warning light fault | <0.01% |
| 138 | Seat belt anchorage fault | <0.01% |
| 139 | Engine mounting worn or broken | <0.01% |
| 140 | Passenger compartment corrosion | <0.01% |
| 141 | Step damaged or insecure | <0.01% |
| 142 | Seat belt or padding damaged | <0.01% |
| 143 | Suspension retaining or locking device fault | <0.01% |
| 144 | Brake master cylinder fault | <0.01% |
| 145 | Full power hydraulic brake fault | <0.01% |
| 146 | Seat belt pre-tensioner fault | <0.01% |
| 147 | Transmission drive belt fault | <0.01% |
| 148 | Outline marker lamp not working | <0.01% |
| 149 | Brake back plate corroded or damaged | <0.01% |
| 150 | Brake pressure or vacuum buildup insufficient | <0.01% |
| 151 | CV joint worn | <0.01% |
| 152 | Vehicle floor corroded | <0.01% |
| 153 | Indicator warning light fault | <0.01% |
| 154 | Semaphore indicator fault | <0.01% |
| 155 | Body strengthening plate corroded | <0.01% |
| 156 | Halfshaft fault | <0.01% |
| 157 | Steering damper fault | <0.01% |
| 158 | Steering lock stop fault | <0.01% |
| 159 | Torque or reaction arm worn | <0.01% |
| 160 | Bonded suspension condition | <0.01% |
| 161 | Brake pedal linkage fault | <0.01% |
| 162 | Hydraulic suspension accumulator fault | <0.01% |
| 163 | Leaf spring broken or corroded | <0.01% |
| 164 | Radius arm worn or corroded | <0.01% |
| 165 | Stub axle worn | <0.01% |
| 166 | Torsion bar worn or corroded | <0.01% |
| 167 | Brake relay lever fault | <0.01% |
| 168 | Brake valve fault | <0.01% |
| 169 | Daytime running lamp not working | <0.01% |
| 170 | Exhaust heat shield or sound insulation damaged | <0.01% |
| 171 | Handbrake mechanism or mounting fault | <0.01% |
| 172 | Steering intermediate drop arm worn | <0.01% |
| 173 | Trailing arm worn or corroded | <0.01% |
| 174 | Brake master cylinder or servo mounting fault | <0.01% |
| 175 | Hazard warning light fault | <0.01% |
| 176 | Load sensing valve fault | <0.01% |
| 177 | Loading door damaged or insecure | <0.01% |
| 178 | Panhard rod worn or corroded | <0.01% |
| 179 | Spring mounting corroded | <0.01% |
| 180 | Speed limiter fault | <0.01% |
| 181 | Access panel damaged or insecure | <0.01% |
| 182 | Air brake cylinder or actuator fault | <0.01% |
| 183 | Axle beam corroded or cracked | <0.01% |
| 184 | Brake clevis joint worn | <0.01% |
| 185 | Dropside damaged or insecure | <0.01% |
| 186 | Hand-operated brake valve condition | <0.01% |
| 187 | Hinged tailboard damaged or insecure | <0.01% |
| 188 | Leaf spring eye worn or broken | <0.01% |
| 189 | Seat belt load limiter fault | <0.01% |
| 190 | Steering head bearings worn | <0.01% |
| 191 | Wheel hub fault | <0.01% |
Showing all 191 reasons — scroll inside the table for the full list.
Mercedes-benz M-class MOT Failures by Category
Total MOT failure occurrences for the Mercedes-benz M-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 M-class problems?
Based on analysis of 874K Mercedes-benz M-class MOT tests from DVSA data, we have 26 identified common problems across 3 generations. The most frequently flagged issue is "Track rod end worn". Brakes is the most common problem category.
Which Mercedes-benz M-class generation has the most problems?
The Mercedes-benz M-class W163 (1997-2005) (1997–2005) has the highest number of identified common problems (22). 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 M-class?
Yes — use the "Tell Us About Your Problem" form on this page. Your report helps other Mercedes-benz M-class owners spot problems early. All submissions are reviewed before being added to the public database.
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