Torque Reduction - Mercedes-Benz OM 457 LA Operating Instructions Manual

Operating restrictions may occur in the form
of torque reduction, thus also limiting output
and speed.
The degree of torque reduction depends on
the vehicle category:
vehicles above 7.5 t: torque reduction by
R
approximately 40%
vehicles below 7.5 t: torque reduction by
R
approximately 25%
Operating restrictions for off-highway
engines with BlueTec
The electronic engine management system
monitors:
emissions-relevant malfunctions in the
R
exhaust gas aftertreatment
malfunctions in the electronic monitoring
R
of the exhaust gas aftertreatment system
consumption, level and quality of the
R
®
AdBlue /DEF reducing agent
the efficiency of the catalytic converter in
R
accordance with the permitted thresholds
for nitric oxide emissions (NOx)
Operating restrictions in the form of torque
reduction and thus output and speed limita-
tion may occur.
Minor operating restriction
The available torque is reduced to roughly
80% of the maximum torque.
Reduction in output during minor operating restric-
tion
®
Operational monitoring
Major operating restriction
The transition between a minor and a major
operating restriction is achieved by a gradual
reduction in engine speed and torque.
The engine torque is linearly reduced to
R
20% of the nominal value.
At the same time, the engine speed is
R
slowly reduced to 1000 rpm.
Types of operating restriction
®
AdBlue /DEF level low
®
Insufficient AdBlue /DEF remaining; warning and
length of operating restriction period (example dis-
play)
Acknowledged fault
A
Minor operating restriction
B
Speed/torque reduction
C
Major operating restriction
D
43
Z