SECTION 04: EXHAUST AND AFTERTREATMENT SYSTEM
10
DOB 2490-2789 | X3-45 Commuter PA1605 Maintenance Manual (Final Version – Rev.2 April 2016)
housing and assure that all the water is
drained at once at the other end of the drain
tube. If tube is clogged, remove tube and
blow compressed air inside in reverse flow;
Check that the warning plate
”THIS DIFFUSER
SURFACE MUST BE FLUSH WITH THE ROOF
SURFACE”
is still in place.
5.
DIESEL EXHAUST FLUID (DEF) TANK
AND INJECTION SYSTEM
The DEF tank and injection system control unit
continuously vary the amount of DEF injected in
response to the engine’s current load conditions.
Diesel Exhaust Fluid (DEF) is stored in a 16
gallons plastic tank located aft of the condenser
compartment.
FIGURE 8: DEF TANK AND PUMP LOCATION
A pump located beside the DEF tank is used to
pressurize the system and deliver the fluid.
A heating coil located inside the tank use engine
coolant to keep the DEF warm during cold
season.
DEF is injected into the exhaust gases through
an injection nozzle located between the DPF
and the catalytic converter (refer to figure 1).
In the catalytic converter, nitrogen oxides are
transformed into harmless nitrogen gas and
water.
The system notifies the driver when it is time to
top up with DEF.
5.1 DIESEL EXHAUST FLUID
When handling DEF solution, it is important that
electrical connectors to be connected or well
encapsulated, otherwise there is a risk that the
DEF will cause oxidation that cannot be
removed. Water or compressed air will not help,
since DEF quickly oxidizes certain metals. If a
disconnected connector comes into contact with
the DEF solution, it must be replaced
immediately to prevent the DEF solution from
creeping further into the copper wiring, which
takes place at a speed of about 2.4 in (60 mm)
per hour.
CAUTION
Diesel Exhaust Fluid (DEF) is a nontoxic
aqueous solution of urea (32.5%) and ultra-
pure water (67.5%). Urea is a compound of
nitrogen that turns to ammonia when heated.
The fluid is non-flammable, and is not
dangerous when handled as recommended.
However, it is highly corrosive to certain
metals, especially copper and brass.
When detaching hoses and components, do
not spill DEF on disconnected or unsealed
connectors. If DEF is spilled on a
disconnected or unsealed connector, the
connector must be removed immediately and
replaced.
Things to know about spilt diesel exhaust fluid
(DEF):
If urea solution comes into contact with the
skin, rinse with plenty of water and remove
contaminated clothing.
If urea solution comes into contact with the
eyes rinse for several minutes and call for
medical help if necessary.
If inhaled breathe fresh air and call for
medical help if necessary.
Do not allow the DEF solution to come into
contact with other chemicals.
The DEF solution is not flammable. If the
DEF solution is exposed to high
temperatures, it breaks down into ammonia
and carbon dioxide.
The DEF solution is highly corrosive to
certain metals, including copper and
aluminum.
If the DEF solution is spilled onto the vehicle,
wipe off the excess and rinse with water.
Spilled DEF solution can form concentrated
white crystals on the vehicle. Rinse off these
crystals with water.
