Diesel Fuel Metering Device, Component Description - Mercedes-Benz OM 471 Introduction Into Service Manual

System components
GF49.20>W>3011H
ENGINES 471.9 in MODEL 963, 964 with CODE (M5Z) Engine version Euro VI
Location
1 Diesel fuel metering device
2 Nozzle unit for DPF regeneration
3 Fuel line
4 Exhaust pipe
5 Coolant line
6 Coolant line
7 Leakage line
The diesel fuel metering device (1) is on the
left>hand side of the engine behind the fuel
system high pressure pump.
Task
The diesel fuel metering device (1) is used to
provide the required quantity of diesel fuel
for injecting into the exhaust pipe (4)
during active diesel particulate filter (DPF)
regeneration.
Design
1 Diesel fuel metering device
2 Nozzle unit for DPF regeneration
3 Fuel line
4 Exhaust pipe
5 Coolant line
B625 Fuel pressure sensor (inlet)
B626 Fuel pressure sensor (outlet)
Y628 Fuel metering valve
Y629 Fuel shutoff valve
The diesel fuel metering device (1) is a
component that is permeated with fuel
channels and has an aluminum body. The
sensors that are placed on it have their
measuring probes inserted into the fuel
channels.
It is connected to the nozzle unit (2) via the
fuel line (3).
Function
When the exhaust aftertreatment control unit (ACM) (A60)
decides that active regeneration of the diesel particulate filter
(DPF) is required on the basis of the values provided by the sensor
system, it sends a request to the engine management control unit
(MCM) (A4). This actuates the fuel shutoff valve (Y629), so that
diesel fuel from the low>pressure circuit enters the component.
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Diesel fuel metering device, component description

– This printout will not be recorded by the update service. Status: 09 / 2011 –
The fuel metering valve (Y628) is also opened at defined intervals.
The calculated quantity of diesel fuel therefore flows into the
feed line to the nozzle unit for DPF regeneration (2).
The two pressure sensors deliver values that are used in the valve
opening time calculation.
20.7.11
W49.20>1017>76
W49.20>1018>76