Determination Of Air Mass, Function - Mercedes-Benz OM 471 Introduction Into Service Manual

Functions
GF07.07>W>3001H
ENGINE 471.9 in MODEL 963
Input signals,
shown with code (M5Z) Euro VI engine version
A4 Engine management control unit (MCM)
B608 Charge air pressure and temperature sensor in charge air
pipe
B611 Temperature sensor downstream of air filter (only for
code (M5Z) Engine version Euro VI)
B617 Charge air temperature sensor in charge air housing
B621 Exhaust gas recirculation (AGR) differential pressure
sensor
CAN 4 Drive train CAN
General information
The air mass, along with the coolant temperature, engine speed
or fuel temperature, is one of the most important factors required
by the engine management to regulate the injection quantity.
The injection quantity can only be exactly calculated with the aid
of the air mass.
Component description for engine
management (MCM) control unit
Charge air pressure and temperature
sensor in charge air pipe, component
description
Component description for temperature
sensor downstream of air filter
Charge air temperature sensor in charge air
housing, component description
EGR differential pressure sensor,
component description
56

Determination of air mass, function

– This printout will not be recorded by the update service. Status: 09 / 2011 –
Function
Determination of the air mass occurs over the engine
management (MCM) control unit (A4). This uses the following
information, which is determined by the charge air pressure and
temperature sensor in charge air pipe (B608), the temperature
sensor downstream of the air filter (B611) > only with code (M5Z)
Euro VI engine version, the exhaust gas recirculation (EGR)
differential pressure sensor (B621) and the charge air temperature
sensor in the charge air housing (B617):
f Mass of the actual suctioned in or supercharged fresh air
f Mass of the actual returned exhaust gases
The engine management (MCM) control unit (A4) can derive the
air mass which is routed to the engine for combustion from these
values.
A4
B608
B611
i Only for vehicles with code (M5Z)
Engine version Euro VI.
B617
B621
2.8.11
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