Adblue“ Line System; Adblue“ Heater; Function Of Adblue“ Heating By Coolant; Function Of Adblue“ Heating By An Electrical Heater - Mercedes-Benz OM 471 Introduction Into Service Manual

AdBlue"/coolant line system
1 Pump module
6 Coolant feed line
7 Coolant return line
AdBlue" line system
The AdBlue" line system lies between the AdBlue" container (5),
pump module (1) and AdBlue" metering device (A67).
The fact that the AdBlue" metering device (A67) is directly
attached to the EATU and is therefore subjected to high
temperatures, AdBlue" is circulated continuously from engine
start and in a certain run>on time after engine stop for
recirculation cooling.
AdBlue" heater
AdBlue" freezes below a temperature of about >13∞C. The
AdBlue" heater ensures that any AdBlue" that has frozen during
periods of non>operation is heated and reliquified and prevents
AdBlue from freezing while driving in cold outside temperatures.
The AdBlue" lines from the AdBlue" container (5) to the pump
module (1) are bundled with the coolant lines and routed
insulated.
The AdBlue" lines between the pump module (1) and the AdBlue"
metering device (A67) are not heated by coolant but instead over
in electrically heated heating elements integrated in the line
sections.
i Introduction of engine OM 471 and exhaust aftertreatment > 09/2011 >
A67 AdBlue" metering device
B74 AdBlue" fill level
sensor/temperature sensor
R6 AdBlue" return line heating element
– This printout will not be recorded by the update service. Status: 09 / 2011 –
R7 AdBlue" intake duct heating
element
R8 AdBlue" pressure line heating
element
Y627 AdBlue" heater coolant solenoid
valve
Function of AdBlue" heating by coolant
The AdBlue" heater consists of the AdBlue" coolant solenoid
valve heater (Y627) which is located on the rear side of the engine
and a coolant line system. The AdBlue" coolant solenoid valve
heater (Y627) is actuated by the engine management (MCM)
control unit (A4). Over the AdBlue" fill level sensor/temperature
sensor (B74) integrated in the AdBlue" container (5), it detects
when the temperature of the tank contents is approaching the
defined limit value of approx. 8∞C. If this is the case and if the
coolant temperature has already reached a temperature of 65∞C,
the AdBlue" heater coolant solenoid valve (Y627) is opened so the
coolant flows through the line system.
Function of AdBlue" heating by an electrical heater
The heating coil of the heating elements integrated in the
AdBlue" lines is switched on and off by the exhaust
aftertreatment (ACM) control unit (A60). Very pertinent here are
also the values which are delivered by the AdBlue" fill level
sensor/temperature sensor (B74).
Functions
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