Adblue“/Coolant Line System - Mercedes-Benz OM 471 Introduction Into Service Manual

AdBlue"/coolant line system
2 Pump module
11 Coolant feed line
12 Coolant return line
AdBlue" line system
The AdBlue" line system extends from the AdBlue" container (3),
the pump module (2) and the AdBlue" metering device (A67).
Because the AdBlue" metering device (A67) is installed onto the
EATU itself, and therefore exposed to high temperatures,
AdBlue" is constantly circulated when the engine starts and in a
specific run>on time after the engine is stopped for recirculation
cooling.
AdBlue" heater
AdBlue" freezes from a temperature of approx. >13 ∞C. The
AdBlue " heater ensures that any AdBlue" that has frozen during
periods of non>operation is heated and reliquified and prevents it
from freezing while driving in cold outside temperatures.
The AdBlue" lines from the AdBlue" container (3) to the pump
module (2) are routed and insulated together with coolant lines.
The AdBlue" lines between the pump module (2) and AdBlue"
metering device (A67) are not electrically heated by the coolant,
but by the heating elements integrated into the line sections.
Exhaust aftertreatment overall network
NOx sensor output for exhaust
aftertreatment unit, component
description
Pump module, component description
Exhaust aftertreatment (ACM) control unit,
component description
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
R8
Y627
Function of AdBlue" heating through coolant
The AdBlue" heater consists of the AdBlue" heater coolant
solenoid valve (Y627), which is located on the rear end of the
engine and a coolant line system. The AdBlue" heater coolant
solenoid valve (Y627) is actuated by the engine management
(MCM) control unit (A4). The AdBlue" fill
level sensor/temperature sensor (B74) integrated in the AdBlue"
container (3) enables it to detect when the temperature of the
container's contents is approaching the limit of approx. 8 ∞C. If this
is the case and if the coolant temperature has already reached
+65 ∞C, the AdBlue" heater coolant solenoid valve (Y627) is
opened is that the coolant can flow through the line system.
Function of AdBlue" heating through electrical heater
The heating coils of the heater elements integrated into the
AdBlue" lines are switched on and off by the exhaust
aftertreatment (ACM) control unit (A60). Decisive here are the
values supplied by the AdBlue" fill level sensor/temperature
sensor (B74).
A57, A57 b1
A58, M25
A60
Functions
W14.40>1561>79
AdBlue" intake duct heating
element
AdBlue" pressure line heating
element
AdBlue" heater coolant solenoid
valve
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