Mercedes GLC Diesel DPF issue

Sounds like a clogged DPF alright. Is the engine light flashing, or is it solid? A flashing light often means stop driving immediately. If the filter is blocked solid, the back pressure will choke the engine. A sensor fault can definitely stop regeneration. Have you checked for any obvious exhaust leaks?

Thank you for your prompt response. The engine light is solid, not flashing. I haven't detected any exhaust leaks, but I confess I haven't performed an exhaustive inspection. Given that a sensor fault could indeed be the culprit preventing regeneration, what specific sensor(s) should I be prioritizing for diagnostic scrutiny? Is there a way to check sensor data without proprietary Mercedes tools?

A solid light is better than flashing, but still not good. Without proper diagnostic tools, it's tricky. You're looking at sensors related to the exhaust system and DPF function; differential pressure sensor (measures pressure before and after the filter), temperature sensors (before and after the DPF - monitors the filter temperature). They provide data for regeneration. If one is off, regeneration won't happen. I'd suggest taking it to a trusted mechanic. A completely blocked DPF can cause more damage.

Understood. Your explanation regarding the differential pressure and temperature sensors is particularly helpful in clarifying the diagnostic landscape. I appreciate the wisdom in seeking professional assistance. As suspected, the diesel particulate filter was indeed defective, and required replacement. The total cost, including labor, amounted to 1550€. Thank you again for your assistance.