POWER TRAIN 16000 SERVICE/MAINTENANCE MANUAL
7-18
Published 05-03-17, Control # 228-03
DEF Dosing System
A diesel exhaust fluid (DEF) supplies the required DEF to the
DEF dosing module (8).
DEF Delivery Heating/Cooling System
Engine Coolant
Warm coolant from the engine is routed to a manifold (1)
where it splits into two paths: one delivers coolant to the heat
exchanger in the DEF tank (4) to keep the DEF warm or to
thaw, and the other delivers coolant to the dosing module (8)
to keep it from overheating. See Figure 7-12
for hose routing
and coolant flow direction.
A solenoid valve (3) adjusts coolant flow to the DEF tank
according to the temperature of the DEF in the tank. If the
tank temperature drops below –4°C (25°F), this solenoid
valve will be signaled to open by the ECM, and engine
coolant will flow through the heat exchanger in the DEF tank.
24 VDC Heating Elements
To keep the DEF flowing during cold temperatures, one
electric heating element is in the DEF supply module and
one element is installed in each DEF line at the module.
These elements come on if the ambient air temperature
sensor reads a temperature below –4°C (25°F).
Maintenance Heating Cycle
The DEF dosing module will not prime the system until every
component is completely defrosted. If ambient conditions
continue to be cold after the system has primed, the ECM will
command a maintenance heating cycle to prevent the DEF
system from refreezing. This feature will cycle the heating on
and off to the DEF lines, DEF tank, and dosing module.
NOTE: DEF will freeze at –11°C (12°F) and when frozen
will expand by 7%. There are no approved
additives to improve the freezing point.
DEF Supply Module
The DEF supply module (5, Figure 7-12) is an electronically
operated pump and metering system controlled by the ECM.
The module pumps DEF to the dosing module which is
mounted on the DRT.
The supply module is heated electrically and has a 10-
micron filter that requires periodic cleaning and inspection.
For filter maintenance intervals, refer to the Cummins engine
manual.
Diesel Exhaust Fluid (DEF)
DEF (or AdBlue in Europe) consists of 32% urea and 68%
de-ionized water. A constant mist of DEF, equal to 2 to 3% of
fuel used, is injected into the DRT. This is about 10 gallons of
DEF per 2 to 3 tanks of fuel.
The engine control module monitors DEF quality via a
sensor in the tank. If poor quality DEF is sensed, an error
code will be set.
NOTE: Do not store DEF for long periods of time. DEF will
deteriorate faster in warmer temperatures. Low-
quality DEF may require the tank to be drained and
the system purged.
WARNING
Personal Injury or Equipment Damage Hazard
Do not remove hoses from or attempt to service the DEF
supply module without first consulting the engine
manufacturer’s instructions. Personal injury and/or
equipment damage may result.
CAUTION
Use Only Approved Replacement Parts
DEF system components are designed to withstand
freezing and to be compatible with DEF fluid and other
unique characteristics of the system. Use of non-
approved replacement parts may result in system
damage.
WARNING
Chemical Hazard!
DEF contains urea. Do not get DEF in your eyes. In case
of contact, immediately flush your eyes with large
amounts of water for a minimum of 15 minutes. Do not
swallow DEF. In the event DEF is ingested, contact a
physician immediately.
CAUTION
Loss of Power or Engine Shutdown Hazard!
If poor-quality DEF or a low-level condition is sensed, an
error code will be set. These conditions can lead to engine
power being reduced (de-rated) by the ECM. If the
condition persists, engine shutdown may occur.
For more information, refer to the Fault Level Indicators
topic in Section 3 of the 16000 Operator Manual.
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