Cadillac XT4 Owner's Manual page 214

Warning (Continued)
safety, handling, and storage
information, see the AdBlue
container label.
Caution
Use only AdBlue that is GM
approved, or fluid containing the
API certified or ISO 22241 label.
The use of other fluids could
damage the system, requiring costly
repairs that will not be covered by
the vehicle warranty.
Caution
Do not mix fuel with AdBlue, and
do not fill AdBlue into the fuel
tank. This could lead to costly
repairs that might not be covered
by the vehicle warranty.
AdBlue is used with diesel engines to
reduce the amount of regulated
emissions produced. The fluid level in
the AdBlue tank must be maintained
for the vehicle to run properly. AdBlue
is not a fuel additive. AdBlue freezes
when exposed to temperatures below
11 °C (12 °F). For AdBlue tank
capacity, see Capacities and
Specifications 0 373.
It is normal to hear the AdBlue
system purge fluid back into the tank
after the vehicle is shut off.
Locating AdBlue
AdBlue can be purchased at your
authorised retailers. Additionally,
some diesel truck filling stations or
retailers may have AdBlue available
for purchase. See Recommended Fluids
and Lubricants 0 368.
DRIVING AND OPERATING
Filling the AdBlue Tank
The blue AdBlue cap is behind the
fuel/AdBlue hatch. If equipped with a
fuel cap, do not remove the fuel and
AdBlue caps at the same time. Fill
diesel fuel and AdBlue independently.
Turn the AdBlue cap anticlockwise to
remove.
In cold conditions, AdBlue can freeze
in the AdBlue filler pipe opening.
If this prevents the filling of the
AdBlue tank, park the vehicle in a
warm garage overnight.
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