Mercedes GLC Hybrid Exhaust Back Pressure Sensor Issue

The warning light, smoke, and DPF issues suggest a faulty exhaust back pressure sensor. Before replacing it, check the sensor's wiring for damage or corrosion. Also, have you retrieved any error codes related to the exhaust back pressure sensor using an OBD-II scanner? These codes could provide more insight.

I visually inspected the wiring, but not with a multimeter. Is that what you meant by 'checking the wiring'? I have an OBD-II scanner error code: P2453, which indicates a problem with the DPF pressure sensor range or performance. Is the DPF pressure sensor the same as the exhaust back pressure sensor? Could the error code confirm the sensor is defective?

The P2453 code suggests a DPF system issue, but the DPF pressure sensor and exhaust back pressure sensor are different and in different locations. It's still probable the exhaust back pressure sensor is defective. The P2453 code indicates potential DPF issues, possibly from the sensor malfunction preventing regeneration. Consult a qualified technician for a comprehensive diagnosis and repair to resolve the vehicle emission issue and DPF concerns.

Understood. Thanks for the clarification. I'll take it to my local mechanic. As a follow-up for anyone else experiencing this: it was indeed the exhaust back pressure sensor. Replacement cost 245€, and that resolved the issue. The warning light and smoke are gone, and the DPF regeneration is working again.