Chevrolet/GMC 2.8L Duramax Diesel Engine Supplement (GMNA-Localizing-
U.S./Canada-14465442) - 2021 - CRC - 2/3/20
18 Driving and Operating
Pickups
Vans2. Open the hood and unwrap the electrical
cord. The cord is in the engine
compartment, on the driver side behind
the battery for pickups, and on the
passenger side for vans.
3. Clean and dry the heater cord and connector ends. Check the heater cord
for damage. If it is damaged, do not use
it. See your dealer for a replacement.
Inspect the cord for damage yearly.
4. Plug it into a normal, grounded 110-volt AC outlet.
{Warning
Improper use of the heater cord or an
extension cord can damage the cord and
may result in overheating and fire.
.Plug the cord into a three-prong
electrical utility receptacle that is
protected by a ground fault detection
function. An ungrounded outlet could
cause an electric shock.
.Use a weatherproof, heavy-duty,
15 amp-rated extension cord if needed.
Failure to use the recommended
extension cord in good operating
condition, or using a damaged heater
(Continued)
Warning (Continued)
or extension cord, could make it
overheat and cause a fire, property
damage, electric shock, and injury.
.Do not operate the vehicle with the
heater cord permanently attached to
the vehicle. Possible heater cord and
thermostat damage could occur.
.While in use, do not let the heater
cord touch vehicle parts or sharp
edges. Never close the hood on the
heater cord.
.Before starting the vehicle, unplug the
cord, reattach the cover to the plug,
and securely fasten the cord. Keep the
cord away from any moving parts.
5. Before starting the engine, be sure to unplug and store the cord as it was
before to keep it away from moving
engine parts and prevent damage.
The length of time the heater should remain
plugged in depends on the outside
temperature. You may wish to use the
coolant heater to improve ease of starting
at temperatures between −18 °C (0 °F) and
−29 °C (−20 °F). Keep the coolant heater
plugged in for a minimum of four hours. At
Chevrolet/GMC 2.8L Duramax Diesel Engine Supplement (GMNA-Localizing-
U.S./Canada-14465442) - 2021 - CRC - 2/3/20
24 Driving and Operating
limited. For the DEF warning light symbol,
seeDiesel Exhaust Fluid (DEF) Warning Light
0 10.
DEF Quality Poor
Use only DEF that is GM approved, or fluid
containing the API certified or ISO 22241
label.
DEF has an expiration date. If the system
detects poor quality, or contaminated or
diluted DEF, the DIC message will display
along with distance until vehicle speed is
limited.
The speed limitation will occur in a series of
steps with the final speed limitation being
8 km/h (5 mph) along with a flashing
warning light and chimes.
Adding fresh DEF to the system may resolve
the problem after several kilometers/miles
of driving, depending on several factors.
If the DIC message persists, see your dealer
or additional DIC messages may display.
Service DEF System
If a problem occurs with the DEF system, a
DIC message displays along with distance
until vehicle speed is limited. The speed limitation will occur in a series of
steps with the final speed limitation being
8 km/h (5 mph) along with a flashing
warning light and chimes.
In some cases, this message will clear itself,
indicating that the DEF system was able to
correct the condition. If the DIC message
persists, see your dealer or additional DIC
messages may display.
Service Emission System
If a problem occurs with the vehicle
emission system, a DIC message displays
along with distance until vehicle speed is
limited. The speed limitation will occur in a
series of steps with the final speed
limitation of 88 km/h (55 mph) and chimes.
In some cases, this message will clear itself,
indicating that the emission system was
able to correct the condition. If the DIC
message persists, see your dealer or
additional DIC messages may display.
Brakes
Exhaust Brake
The exhaust brake can be used to enhance
the vehicle brake system and reduce brake
lining wear.Downshifts may be automatically selected
to increase engine speed, which increases
the effectiveness of the exhaust brake. The
number of downshifts selected is
determined by the length of time the brakes
are applied and the rate the vehicle is
slowing. The system delivers the correct
amount of braking to assist in vehicle
control. The heavier the vehicle load, the
more active the engine exhaust brake will
be. Use of the exhaust brake will help
maintain vehicle speed when used with
cruise control. See
“Cruise Control”in the
owner’s manual.
Automatic downshifts will not occur if the
vehicle is in Range Selection Mode. See
“Manual Mode” in the owner’s manual.
The exhaust brake only activates when the
transmission torque converter is locked. This
can vary based on vehicle speed, gear,
and load.
To activate the system, press the switch on
the center stack.
