Table of Contents
Advertisement
Exhaust gas recirculation path
Part of the exhaust gas enters the exhaust gas recircu-
lation system via the exhaust manifold.
The EGR path is made up of the following components:
• EGR pre-cooler
• EGR actuator
• EGR bypass flap
• EGR cooler
The incoming quantity of exhaust gas is controlled by
the EGR actuator.
EGR path
1
EGR actuator
2
Vacuum unit
3
EGR bypass
– This printout will not be recorded by the update service. Status: 09 / 2008 –
The CDI control unit actuates the EGR actuator via a
pulse width modulated signal, causing the EGR actu-
ator to increase or reduce the size of the opening
cross-section of the EGR valve. In order to further
improve the efficiency, the exhaust gas can be
directed via the EGR cooler and cooled further
depending on the requirement.
However, if the temperature of the incoming exhaust
gas is too low, the path to the EGR cooler is closed via
a bypass flap and the exhaust gas is guided directly to
the charge air manifold. The switchover valve for the
bypass flap is controlled by a vacuum unit.
Introduction of New Generation of 4-Cylinder Inline Engines, OM 651
Exhaust system
4
EGR cooler
5
EGR pipe
6
EGR pre-cooler
33
q
Hide quick links:
Advertisement
Table of Contents
