2009 Mercedes A-Class 1.5L Petrol · FN09 KLM

The most recent DVSA examination on 12 September 2025 resulted in a Pass, but only after the same date recorded a Fail with three PRS (present and rectify at test) items, namely an inoperative horn, an illuminated engine management malfunction indicator lamp, and an inoperative number plate lamp. Notably, the engine MIL has now failed three separate tests across the recorded history, indicating a chronic or recurring fault rather than a one-off event, and a horn failure also featured on the 2024 test. The pattern over the past four years demonstrates a worsening rather than improving trend, with failures increasing in severity; the 2024 test included a Dangerous failure for front tyre tread depth below 1.6mm and a Major failure for rear shock absorbers showing negligible damping effect. Two advisories were also issued at the 2025 test relating to the offside front lower engine mounting showing damage and the nearside front lower gearbox mounting being defective, both of which warrant close attention even though they were not failed items at that time. With a recorded mileage of 124,565 on a 2009 vehicle, this A-Class has covered approximately 7,327 miles per year, which sits broadly within typical parameters for its age. There are no large unexplained gaps in the recorded mileage, suggesting consistent use rather than prolonged standing. That said, the MOT frequency has been annual as expected, and the mileage accumulation between tests appears steady, meaning consumable wear from mileage, such as brake components, tyres, and drivetrain items, should be proportionate to the odometer reading rather than accelerated by abuse. The relatively average annual mileage suggests the vehicle has been used regularly enough to avoid the worst of standing-related issues such as seized calipers or severe underbody corrosion, although age-related deterioration of rubber and electrical components remains highly relevant. Given the recurring engine MIL issue, the prospective buyer should investigate the root cause thoroughly before purchase, as persistent MIL illumination on a Mercedes-Benz of this era commonly relates to lambda sensors, mass airflow sensors, ignition coils, or evaporative emissions faults, and an unresolved issue may have longer-term consequences for catalytic converter efficiency, fuel economy, and exhaust emissions compliance. A pre-purchase diagnostic read using a Mercedes-compatible OBD tool is strongly advised to retrieve any stored fault codes and confirm whether the MIL was simply reset without repair. On a road test, listen for any irregular idling, hesitation under acceleration, or unusual exhaust sounds, and verify that the engine warning light extinguises promptly after start-up and remains off under load. The damaged engine mounting and defective gearbox mounting advisories should also be physically inspected; with the engine running from cold and during a blip of the throttle, listen for excessive vibration or clunks transmitted into the cabin, as worn mounts can cause drivetrain shunt on pull-away and allow components to contact the body or exhaust. Beyond the recorded defects, age-appropriate inspections remain essential on a 17-year-old vehicle regardless of mileage. The track rod end play noted at the 2024 test should be rechecked, as wear at this joint progresses steadily and produces vague steering, uneven front tyre wear particularly on the inner or outer shoulders, and clonking noises over bumps. The 2023 advisory regarding pitted or scored rear brake discs suggests surface corrosion has developed, which on test would manifest as brake shudder or pulsation under firm application; inspect the discs visually for lipping and ridge formation, and verify the handbrake holds on an incline. Check all tyres, including the rear pair, for age-related sidewall perishing and cracking, as rubber degrades from UV exposure and standing periods regardless of tread depth. Confirm the 12V battery is recent, as Mercedes-Benz electrical systems are sensitive to voltage drop and a weak battery can trigger spurious warning lights including the MIL. Finally, verify the service history stamps, particularly for timing chain replacement which is a known consideration on higher-mileage petrol Mercedes units, and ensure that brake fluid, coolant, and transmission oil have been changed on calendar-based intervals rather than purely by mileage, as fluid degradation occurs with time irrespective of use.