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A very common problem with the Mercedes Citan 1.5 dCi.

Model: Mercedes Citan W420 - Years 2021-2026
Part: Checks and maintenance

A very common problem on the Mercedes Citan 1.5 dCi is the breakage of the differential pressure tube, which connects the DPF to the pressure sensor. The tube is often made of rigid plastic, or rubber not resistant enough to heat; moreover, it is located in a very crowded engine compartment and subject to vibrations, high temperatures, and mechanical stresses. If this tube breaks or comes loose, the pressure sensor no longer correctly reads the pressure difference between the inlet and outlet of the DPF, so the ECU receives incorrect information. As a result, the yellow engine light comes on; an error message on the display "start engine to regenerate particulate filter" (even if not needed); emergency mode can be activated, with a reduction in engine power. The errors that can be read with an OBD tool are P2452 (loss in the differential pressure sensor circuit) and P2453 (sensor signal out of range). For the repair, there are metal repair kits available (AliExpress code 1005007508965535 priced at 22.74 euros, free delivery).

Posted on 13 September 2025 by ScegliAuto

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