Diesel Exhaust Fluid
Diesel Exhaust Fluid (DEF) is used with diesel engines to reduce the amount of regulatedemissions produced. The DEF system must be maintained for the vehicle to run properly.
Locating Diesel Exhaust Fluid
DEF can be purchased at a Chevrolet or GMC dealer. It can also be purchased at authorizedvehicle and truck dealerships. Additionally, some diesel truck fueling stations orretailers may have DEF for purchase. For vehicles with an active OnStar® subscription,OnStar can help to locate a DEF retailer. For more information on locating DEF seewww.afdc.energy.gov/afdc/locator/def/. See “Customer Assistance Offices” in the ownermanual forphone numbers to assist you in contacting a GM dealer. SeeRecommended Fluids and Lubricants.
As the DEF tank becomes low on fluid, warnings begin with approximately 1600 km-(1,000mi) of remaining range. These warnings will increase in intensity as the tank becomesempty. Once the tank is empty, the vehicle speed will be limited. If there is an issuewith the quality of the fluid or the exhaust fluid system, warnings will be displayedin the Driver Information Center (DIC). SeeDiesel Exhaust Fluid.