Component Description For The Differential Pressure Sensor (DPF) - GF07.04-S-6122SA

ENGINES 642.8 in MODEL 906

with CODE (MG5) Engine OM 642 DE 30 LA, 140 kW (190 hp) 3800 RPM

except CODE (ZU7) National version for Canada

except CODE (ZU8) National version for USA

ENGINES 642.8 in MODEL 639

with CODE (XZ1) Model generation 1

with CODE (MZ0) BlueEFFICIENCY

Illustrated on model 906

Fig 1: Catalytic Converter With Diesel & DPF Differential Pressure Sensor Component Locations (Illustrated On Engine 642, Model 906)

Courtesy of MERCEDES-BENZ USA

Location

The DPF pressure differential sensor is located on the RH side on the cylinder head.

Task

The diesel particulate filter (DPF) differential pressure sensor detects the exhaust pressure differential upstream and downstream of the DPF.

The CDI control unit (N3/30) determines the soot and ash loading of the DPF with the aid of the DPF differential pressure sensor.

Front view

Fig 2: Identifying Diesel Particulate Filter Differential Pressure Sensor Components

Courtesy of MERCEDES-BENZ USA

Design

The DPF pressure differential sensor consists of a piezo resistant pressure sensor element, electronics for signal amplification and temperature compensation. All components are integrated in a silicon chip. The silicon chip is protected from corrosion by a protective gel and is cast in a plastic housing.

Function

The DPF pressure differential sensor detects the difference in the exhaust pressure upstream and downstream of the DPF over the exhaust pressure connections upstream and downstream of the DPF over the pressure lines.

The pressure difference between the exhaust gas pressures upstream and downstream of DPF has an effect on the piezo resistant pressure sensor element.

This generates a voltage, which is amplified by the integrated silicon chip and sent as a voltage signal to the CDI control unit.