2019 GMC SIERRA warning

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-1500-11698638) - 2019 - CRC - 5/14/19
Vehicle Care 335
3. Connect the vehicle to abattery charger.
4. Turn the ignition on for Key Access vehicles or to Service
Only for Keyless Access
vehicles. See Ignition Positions
(Key Access) 0220 or
Ignition Positions (Keyless
Access) 0222.
5. Turn off the air conditioning.
6. Set the parking brake.
7. At the same time, press the accelerator and the brake for
automatic transmission
vehicles for two seconds, then
release.
At the end of the cycle, check the
coolant level in the surge tank and
add coolant if it is low. Turn off the
vehicle, allow the Electronic Control
Module (ECM) to go to sleep, about
2 minutes, and repeat Steps 3-7.
Listen for pump activation and
movement of the control valves
while watching the level of the
coolant in the surge tank. If the tank
empties, turn the ignition off, carefully remove the surge tank cap,
refill to the indicated mark, and
repeat Steps 3-6. The fill and air
removal process will run for
approximately 10 minutes.
How to Add Coolant to the
Coolant Surge Tank for
Gasoline Engines Except L3B
If the vehicle has a diesel engine,
see
“Cooling System” in the
Duramax diesel supplement for the
proper coolant fill procedure.
{Warning
Spilling coolant on hot engine
parts can burn you. Coolant
contains ethylene glycol and it will
burn if the engine parts are hot
enough.
{Warning
Plain water, or other liquids such
as alcohol, can boil before the
proper coolant mixture will. With
plain water or the wrong mixture,
the engine could get too hot but
there would not be an overheat
warning. The engine could catch
fire and you or others could be
burned.
{Warning
Steam and scalding liquids from a
hot cooling system are under
pressure. Turning the pressure
cap, even a little, can cause them
to come out at high speed and
you could be burned. Never turn
the cap when the cooling system,
including the pressure cap, is hot.
Wait for the cooling system and
pressure cap to cool.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-1500-11698638) - 2019 - CRC - 5/14/19
Vehicle Care 337
The vehicle has several indicators
to warn of engine overheating.
There is a coolant temperature
gauge in the vehicle's instrument
cluster. SeeEngine Coolant
Temperature Gauge 0147.
In addition, there are ENGINE
OVERHEATED STOP ENGINE,
ENGINE OVERHEATED IDLE
ENGINE, and ENGINE POWER IS
REDUCED messages in the Driver
Information Center (DIC).
If the decision is made not to lift the
hood when this warning appears,
get service help right away. See
Roadside Assistance Program
0 442.
If the decision is made to lift the
hood, make sure the vehicle is
parked on a level surface.
2.7L L4, 4.3L V6, 5.3L V8, and 6.2L
V8 Engines
Check to see if the engine cooling
fans are running. If the engine is
overheating, the fans should be running. If they are not, do not
continue to run the engine. Have the
vehicle serviced.
If Steam is Coming from the
Engine Compartment
{Warning
Steam and scalding liquids from a
hot cooling system are under
pressure. Turning the pressure
cap, even a little, can cause them
to come out at high speed and
you could be burned. Never turn
the cap when the cooling system,
including the pressure cap, is hot.
Wait for the cooling system and
pressure cap to cool.
If No Steam is Coming from
the Engine Compartment
The ENGINE OVERHEATED STOP
ENGINE or the ENGINE
OVERHEATED IDLE ENGINE
message, along with a low coolant
condition, can indicate a serious
problem.The 2.7L engine will shut down
automatically if the ENGINE
OVERHEATED STOP ENGINE
message displays.
If there is an engine overheat
warning, but no steam is seen or
heard, the problem may not be too
serious. Sometimes the engine can
get a little too hot when the vehicle:
.
Climbs a long hill on a hot day.
. Stops after high-speed driving.
. Idles for long periods in traffic.
. Tows a trailer; see Trailer Towing
0 286.
If the ENGINE OVERHEATED
STOP ENGINE or the ENGINE
OVERHEATED IDLE ENGINE
message appears with no sign of
steam, try this for a minute or so: 1. Turn the air conditioning off.
2. Turn the heater on to the highest temperature and to the
highest fan speed. Open the
windows as necessary.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-1500-11698638) - 2019 - CRC - 5/14/19
338 Vehicle Care
3. When it is safe to do so, pull offthe road, shift to P (Park) or
N (Neutral) and let the
engine idle.
If the temperature overheat gauge is
no longer in the overheat zone or an
overheat warning no longer
displays, the vehicle can be driven.
Continue to drive the vehicle slowly
for about 10 minutes. Keep a safe
vehicle distance from the vehicle in
front. If the warning does not come
back on, continue to drive normally
and have the cooling system
checked for proper fill and function.
If the warning continues, pull over,
stop, and park the vehicle
right away.
If there is still no sign of steam and
the vehicle is equipped with an
engine driven cooling fan, push
down the accelerator until the
engine speed is about twice as fast
as normal idle speed for at least
five minutes while the vehicle is
parked. If the warning is still there,
turn off the engine and get everyone
out of the vehicle until it cools down. If there is no sign of steam, idle the
engine for five minutes while
parked. If the warning is still
displayed, turn off the engine until it
cools down.
Overheated Engine
Protection
Operating Mode
If an overheated engine condition
exists and the ENGINE POWER IS
REDUCED message displays, an
overheat protection mode which
alternates firing groups of cylinders
helps to prevent engine damage. In
this mode, a loss in power and
engine performance will be noticed.
This operating mode allows the
vehicle to be driven to a safe place
in an emergency. Driving extended
distances and/or towing a trailer in
the overheat protection mode
should be avoided.
Caution
After driving in the overheated
engine protection operating
mode, the engine oil will be
severely degraded. Any repairs
performed before the engine is
cool may cause engine damage.
Allow the engine to cool before
attempting any repair. Repair the
cause of coolant loss, change the
oil, and reset the oil life system.
See
Engine Oil 0326.
Engine Fan
The vehicle has electric cooling
fan(s). The fans may be heard
spinning at low speed during most
everyday driving. The fans may turn
off if no cooling is required. Under
heavy vehicle loading, trailer towing,
high outside temperatures,
or operation of the air conditioning
system, the fans may change to
high speed and an increase in fan
noise may be heard. This is normal
and indicates that the cooling
system is functioning properly. The

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-1500-11698638) - 2019 - CRC - 5/14/19
340 Vehicle Care
Brakes
Disc brake pads have built-in wear
indicators that make a high-pitched
warning sound when the brake pads
are worn and new pads are needed.
The sound can come and go or be
heard all the time the vehicle is
moving, except when applying the
brake pedal firmly.
{Warning
The brake wear warning sound
means that soon the brakes will
not work well. That could lead to
a crash. When the brake wear
warning sound is heard, have the
vehicle serviced.
Caution
Continuing to drive with worn-out
brake pads could result in costly
brake repair.Some driving conditions or climates
can cause a brake squeal when the
brakes are first applied or lightly
applied. This does not mean
something is wrong with the brakes.
Properly torqued wheel nuts are
necessary to help prevent brake
pulsation. When tires are rotated,
inspect brake pads for wear and
evenly tighten wheel nuts in the
proper sequence to torque
specifications in
Capacities and
Specifications 0435.
Brake linings should always be
replaced as complete axle sets.
Brake Pedal Travel
See your dealer if the brake pedal
does not return to normal height,
or if there is a rapid increase in
pedal travel. This could be a sign
that brake service may be required.
Replacing Brake System Parts
Always replace brake system parts
with new, approved replacement
parts. If this is not done, the brakes
may not work properly. The braking
performance expected can change in many other ways if the wrong
replacement brake parts are
installed or parts are improperly
installed.
Brake Pad Life System
When to Change Brake Pads
This vehicle has a system that
estimates the remaining life of the
front and rear brake pads. Brake
pad life is displayed in the Driver
Information Center (DIC), along with
a percentage for each axle. The
system must be reset every time the
brake pads are changed.
When the system has determined
that the brake pads need to be
replaced, a message will display,
which may include mileage
remaining.
Brake pads should always be
replaced as complete axle sets.
How to Reset the Brake Pad
Life System
The system will automatically detect
when significantly worn brake pads
are replaced. When the ignition is

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-1500-11698638) - 2019 - CRC - 5/14/19
Vehicle Care 341
turned on after new pads and wear
sensors are installed, a message
will display. Follow the prompts to
reset the system.
The brake pad life system can also
be manually reset:1. Display Brake Pad Life on the DIC. See Driver Information
Center (DIC) (Midlevel and
Uplevel) 0163 or
Driver Information Center (DIC)
(Base Level) 0161.
2. Press the thumbwheel or the trip odometer reset stem if the
vehicle does not have DIC
buttons. Select front or rear
pads as appropriate.
3. Select YES on the confirmation message, or press the trip
odometer reset stem on a base
level DIC. Repeat for pads on
the other axle if they were also
replaced.How to Disable the Brake Pad
Life System
The brake pad life system can be
turned off. This may be necessary if
aftermarket brake pads without wear
sensors are installed. When the
system is turned off, the front and
rear brake pad life percentages will
not display. However, the built-in
wear indicators that make a
high-pitched warning sound when
the brake pads are worn can still
determine when the pads should be
replaced. See Brakes0340.
To turn off the brake pad life system: 1. Display Brake Pad Life on the DIC. See Driver Information
Center (DIC) (Midlevel and
Uplevel) 0163 or
Driver Information Center (DIC)
(Base Level) 0161.
2. Select DISABLE.
To turn the brake pad life system
back on, follow the above steps but
select ENABLE in Step 2.
Brake Fluid
The brake master cylinder reservoir
is filled with GM approved DOT 4
brake fluid as indicated on the
reservoir cap. See Engine
Compartment Overview 0321 for
the location of the reservoir.
Checking Brake Fluid
With the vehicle in P (Park) on a
level surface, the brake fluid level
should be between the minimum
and maximum marks on the brake
fluid reservoir.
There are only two reasons why the
brake fluid level in the reservoir may
go down:
. Normal brake lining wear. When
new linings are installed, the
fluid level goes back up.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-1500-11698638) - 2019 - CRC - 5/14/19
342 Vehicle Care
.A fluid leak in the brake
hydraulic system. Have the
brake hydraulic system fixed.
With a leak, the brakes will not
work well.
Always clean the brake fluid
reservoir cap and the area around
the cap before removing it.
Do not top off the brake fluid.
Adding fluid does not correct a leak.
If fluid is added when the linings are
worn, there will be too much fluid
when new brake linings are
installed. Add or remove fluid, as
necessary, only when work is done
on the brake hydraulic system.
{Warning
If too much brake fluid is added, it
can spill on the engine and burn,
if the engine is hot enough. You
or others could be burned, and
the vehicle could be damaged.
Add brake fluid only when work is
done on the brake hydraulic
system. When the brake fluid falls to a low
level, the brake warning light comes
on. See
Brake System Warning
Light 0153.
Brake fluid absorbs water over time
which degrades the effectiveness of
the brake fluid. Replace brake fluid
at the specified intervals to prevent
increased stopping distance. See
Maintenance Schedule 0420.
What to Add
Use only GM approved DOT 4
brake fluid from a clean, sealed
container. See Recommended
Fluids and Lubricants 0430.
{Warning
The wrong or contaminated brake
fluid could result in damage to the
brake system. This could result in
the loss of braking leading to a
possible injury. Always use the
proper GM approved brake fluid.
Caution
If brake fluid is spilled on the
vehicle's painted surfaces, the
paint finish can be damaged.
Immediately wash off any painted
surface.
Battery - North America
The original equipment battery is
maintenance free. Do not remove
the cap and do not add fluid.
Refer to the replacement number
shown on the original battery label
when a new battery is needed. See
Engine Compartment Overview
0321 for battery location.
Stop/Start System
Vehicles equipped with a 2.7L L3B,
3.0L LM2, 5.3L L84 or 6.2L L87 are
equipped with a Stop/Start system
to shut off the engine to help
conserve fuel. See Stop/Start
System 0225.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-1500-11698638) - 2019 - CRC - 5/14/19
Vehicle Care 343
Vehicles with the Stop/Start system
have an Absorbed Glass Mat (AGM)
12-volt battery. Installation of a
standard 12-volt battery will result in
reduced 12-volt battery life. When
using a 12-volt battery charger on
the 12-volt AGM battery, some
chargers have an AGM battery
setting on the charger. If available,
use the AGM setting on the charger
to limit charge voltage to 14.8 volts.
Follow the charger manufacturer’s
instructions.
{Warning
WARNING: Battery posts,
terminals, and related
accessories contain lead and lead
compounds, chemicals known to
the State of California to cause
cancer and birth defects or other
reproductive harm. Batteries also
contain other chemicals known to
the State of California to cause
cancer. WASH HANDS AFTER
HANDLING. For more information
go to www.P65Warnings.ca.gov/
passenger-vehicle. See
California Proposition
65 Warning 0318 and the back
cover.
Vehicle Storage
{Warning
Batteries have acid that can burn
you and gas that can explode.
You can be badly hurt if you are
not careful. See Jump Starting -
North America 0400 for tips on
working around a battery without
getting hurt.
Infrequent Usage: Remove the
black, negative (−) cable from the
battery to keep the battery from
running down.
Extended Storage: Remove the
black, negative (−) cable from the
battery or use a battery trickle
charger.
Negative Battery Cable
Disconnection
{Warning
Before disconnecting the negative
battery cable, turn off all features,
turn the ignition off, and remove
the key, if equipped, from the
vehicle. If this is not done, you or
others could be injured, and the
vehicle could be damaged.
Caution
If the battery is disconnected with
the ignition on or the vehicle in
Retained Accessory Power
(RAP), the OnStar back-up
battery will be permanently
discharged and will need to be
replaced.
1. Make sure the lamps, features, and accessories are turned off.
2. Turn the ignition off and remove the key, if equipped.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-1500-11698638) - 2019 - CRC - 5/14/19
348 Vehicle Care
Insulation:
Removal of the noise shields or any
underhood insulation.
Engine:
Removal or rendering the engine
speed governor, if equipped,
inoperative so as to allow engine
speed to exceed manufacturer
specifications.
Fan and Drive:
.Removal of the fan clutch,
if equipped, or rendering the
clutch inoperative.
. Removal of the fan shroud,
if equipped.
Air Intake:
. Removal of the air cleaner
silencer.
. Modification of the air cleaner.
Exhaust:
. Removal of the muffler and/or
resonator.
. Removal of the exhaust pipes
and exhaust pipe clamps.Starter Switch Check
{Warning
When you are doing this
inspection, the vehicle could
move suddenly. If the vehicle
moves, you or others could be
injured.
1. Before starting this check, be sure there is enough room
around the vehicle.
2. Apply both the parking brake and the regular brake.
Do not use the accelerator
pedal, and be ready to turn off
the engine immediately if it
starts.
3. Try to start the engine in each gear. The vehicle should start
only in P (Park) or N (Neutral).
If the vehicle starts in any other
position, contact your dealer for
service.
Ignition Transmission
Lock Check
If equipped with Key Access
ignition, while parked, and with the
parking brake set, try to turn the
ignition off in each shift lever
position. The ignition should turn to
off only when the shift lever is in
P (Park).
The ignition key should come out
only when the ignition is off. Contact
your dealer if service is required.
Park Brake and P (Park)
Mechanism Check
{Warning
When you are doing this check,
the vehicle could begin to move.
You or others could be injured
and property could be damaged.
Make sure there is room in front
of the vehicle in case it begins to
roll. Be ready to apply the regular
brake at once should the vehicle
begin to move.