GMC duramax diesel 2016 Supplement Manual page 41

40 Driving and Operating
Locating Diesel Exhaust Fluid
DEF can be purchased at a
Chevrolet or GMC dealer. It can
also be purchased at authorized
vehicle and truck dealerships.
Additionally, some diesel truck
fueling stations or retailers may
have DEF for purchase. For
vehicles with an active OnStar
subscription, OnStar can help to
locate a DEF retailer. See
Customer Assistance Offices in
the owner manual for phone
numbers to assist in contacting a
GM dealer. See Recommended
Fluids and Lubricants 0 121.
Filling the DEF Tank
Caution
Use only DEF 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.
It is recommended to fill the DEF
tank. For DEF tank capacity see
Capacities and Specifications 0 126.
Do not overfill the DEF tank. When
fluid reaches the top of the fill pipe,
stop filling.
If you spill DEF on the vehicle while
filling the tank, rinse the area with
water and wipe the surface with a
damp cloth.
DEF Fill - Van Model Shown,
4-Cylinder Pickups Similar
For vans and 4-cylinder pickups, the
DEF fill is behind the fuel fill door.
The DEF cap is blue, and the diesel
cap is green.
The fill tube location for chassis-cab
and cutaway vans finished by an
upfitter will vary. Check the upfitter
manual.
DEF Fill - 8-Cylinder Pickups
For 8 Cylinder pickups, the DEF fill
is under the hood, on the passenger
side, at the back of the engine
compartment. The DEF cap is blue.
In certain cold conditions, it is
possible to find some frozen DEF in
the DEF fill pipe opening. If this
condition prevents the filling of a
DEF tank, place the vehicle in a
warm garage overnight.