Mercedes-Benz W204 particulate filter differential pressure sensor fault
W204 diesel: what causes a DPF differential pressure sensor fault and how does it show?
The fault can put the car into limp mode and light the engine warning light. Codes include P2453, P2454, P2455 and P244B. The cause can be the sensor itself, a loose connector or water collected in the sensor hoses, which damages the sensor when it freezes.
What should be checked before replacing the differential pressure sensor?
Replacing the sensor is a common repair, but it does not always remove the fault. Check the connector and hoses first: the connector pins may have loosened, and there may be water in the hoses. Clean the connector and the end of the sensor and spray contact spray into the connector. If the fault remains, read the code with a Mercedes-Benz diagnostic tool.
Where is the DPF differential pressure sensor on the W204?
The location depends on the engine. On the OM646 the sensor is on the side of the engine on a piece of sheet metal, on the OM651 between the air filter housing and the bulkhead, and on the OM642 under the car at the rear end of the gearbox. The hoses are tight and can break when removed. The sensor is a different component from the boost pressure sensor.