2021 Mercedes-Benz Sprinter 315 Progressive CDI 1.9L Diesel · MF71 TYA

A pattern of mechanical concern emerges around the engine management system on this 2021 Mercedes-Benz Sprinter, most notably demonstrated by the failure recorded on 12 June 2025 for an inoperative or malfunctioning engine MIL (Malfunction Indicator Lamp). The vehicle returned to test the following day and passed without advisories, suggesting either a cleared fault or a repaired sensor or emissions component at that point. The most recent test on 8 June 2026 passed cleanly from a defect standpoint, but carried advisories on both front inner brake discs showing wear, which indicates the braking system is entering a measurable service interval. With three tests recorded and one failure on record, the roadworthiness trend is mixed rather than consistently strong, and the engine MIL fault should be regarded as a pending question rather than a closed chapter. Mileage on this Sprinter stands at 131,385 miles over approximately five years, equating to an annual accumulation of roughly 26,277 miles, which is high for a vehicle of its age and well above typical commercial or private use averages. This level of sustained mileage places proportionally greater demand on the clutch, dual-mass flywheel, turbocharger, injectors, suspension bushes, and braking components than would be seen on a lower-mileage example. There are no significant gaps in the testing history, with all three MOT records falling within recent consecutive years, indicating the vehicle has been in continuous service rather than laid up. A consistently high-mileage commercial platform of this type typically shows accelerated wear on front suspension components, prop shaft bearings, and rear leaf or coil hardware depending on specification, all of which warrant direct inspection given the accumulated distance. Given that the engine MIL was the headline failure, the buyer should investigate the specific diagnostic trouble codes stored in the ECU using a Mercedes-compatible diagnostic tool such as STAR Diagnosis or a competent aftermarket reader. Recurring MIL faults on the OM654 engine family have been associated with AdBlue system faults, NOx sensor failures, EGR valve issues, and DPF pressure sensor anomalies, any of which could resurface and trigger another test failure. On a test drive, the driver should observe the dashboard for the orange coil or emissions warning light at ignition, watch for sluggish throttle response, intermittent loss of power, or excessive smoke from the exhaust, and listen for any unusual ticking or rattling from the engine bay under load. It is also worth confirming that any recent repair work is fully documented, as intermittent MIL faults can clear without addressing the underlying cause and return within months. The front brake disc advisories recorded on the latest test are a separate but tangible service item. Inner disc wear of this nature on a heavy commercial vehicle often points to uneven wear patterns, potentially caused by binding calipers, worn caliper guide pins, or a sticking handbrake mechanism. During the road test, the driver should feel for any pulling to one side under braking, listen for grinding or scraping noises, and check for a hot wheel or smell of burning after sustained stops. Visually, the buyer should inspect the inner faces of both front discs through the wheel spokes for a pronounced lip, blueing from heat, or surface scoring, and confirm the brake fluid is due for replacement in line with manufacturer schedules. Beyond the recorded items, given the mileage, particular attention should be paid to the condition of the front lower control arm bushes, anti-roll bar links, and any signs of fluid leakage from the steering rack or rear differential, as these are typical wear points on high-mileage Sprinters and would not necessarily have been flagged in a standard MOT.