
GMC Savana Owner Manual (GMNA-Localizing-U.S./Canada-14583543) -
2021 - crc - 7/10/20
Driving and Operating 157
Lane Departure Warning (LDW)
If equipped, LDW may help avoid crashes
due to unintentional lane departures. LDW
uses a camera sensor to detect the lane
markings at speeds of 56 km/h (35 mph) or
greater. It may provide an alert if the
vehicle is crossing a lane without using a
turn signal in that direction. LDW light will
not alert if the turn signal is active in the
direction of lane departure, or if LDW
detects that you are accelerating, braking or
actively steering.
{Warning
The LDW system does not steer the
vehicle. The LDW system may not:
.Provide enough time to avoid a crash.
.Detect lane markings under poor
weather or visibility conditions. This
can occur if the windshield or
headlamps are blocked by dirt, snow,
or ice; if they are not in proper
condition; or if the sun shines directly
into the camera.
.Detect road edges.
.Detect lanes on winding or hilly roads.(Continued)
Warning (Continued)
If LDW only detects lane markings on one
side of the road, it will only warn you
when departing the lane on the side
where it has detected a lane marking.
Always keep your attention on the road
and maintain proper vehicle position
within the lane, or vehicle damage,
injury, or death could occur. Always keep
the windshield, headlamps, and camera
sensors clean and in good repair. Do not
use LDW in bad weather conditions.
How the System Works
LDW utilizes a camera sensor installed on
the windshield ahead of the rearview mirror
to detect lane markings.
To turn LDW on and off, press
@on the
center stack. The control indicator will light
when LDW is on. When LDW is on,
@is
green if LDW is available to warn of a lane
departure. If the vehicle crosses a detected
lane marking without using the turn signal
in that direction,
@changes to amber and
flashes. Additionally, there will be three
beeps on the right or left, depending on the
lane departure direction. LDW will not alert if the turn signal is active in the direction of
lane departure, or if LDW detects that you
are accelerating, braking or actively steering.
Fuel
Top Tier Fuel
GM recommends the use of TOP TIER
Detergent Gasoline to keep the engine clean,
reduce engine deposits, and maintain
optimal vehicle performance. Look for the
TOP TIER Logo or see www.toptiergas.com
for a list of TOP TIER Detergent Gasoline
marketers and applicable countries.

GMC Savana Owner Manual (GMNA-Localizing-U.S./Canada-14583543) -
2021 - crc - 7/10/20
Driving and Operating 159
Warning (Continued)
.Read and follow all the instructions on
the fuel pump island.
.Turn off the engine when refueling.
.Keep sparks, flames, and smoking
materials away from fuel.
.Do not leave the fuel pump
unattended.
.Avoid using electronic devices while
refueling.
.Do not re-enter the vehicle while
pumping fuel.
.Keep children away from the fuel
pump and never let children
pump fuel.
.Before touching the fill nozzle, touch a
metallic object to discharge static
electricity from your body.
.Fuel can spray out if the fuel cap is
opened too quickly. This spray can
happen if the tank is nearly full, and is
more likely in hot weather. Open the
fuel cap slowly and wait for any hiss
noise to stop, then unscrew the cap all
the way.
Turn the fuel cap counterclockwise to
remove. When refueling, hang the fuel cap
from the hook on the fuel door. Fully insert
and latch the fill nozzle, begin fueling.
{Warning
Overfilling the fuel tank by more than
three clicks of a standard fill nozzle may
cause:
.Vehicle performance issues, including
engine stalling and damage to the fuel
system.
.Fuel spills.
.Under certain conditions, fuel fires.Be careful not to spill fuel. Wait five seconds
after you have finished pumping before
removing the fill nozzle. Clean fuel from
painted surfaces as soon as possible. See
Exterior Care
0241. Reinstall the cap by
turning it clockwise until it clicks. Push the
fuel door closed.
{Warning
If a fire starts while you are refueling, do
not remove the fill nozzle. Shut off the
flow of fuel by shutting off the pump or
by notifying the station attendant. Leave
the area immediately.
Caution
If a new fuel cap is needed, get the right
type of cap from your dealer. The wrong
type of fuel cap may not fit properly,
may turn on the malfunction indicator
lamp, and could damage the fuel system
and emissions system. See Malfunction
Indicator Lamp (Check Engine Light) 076.

GMC Savana Owner Manual (GMNA-Localizing-U.S./Canada-14583543) -
2021 - crc - 7/10/20
174 Driving and Operating
The seven-wire harness contains the
following trailer circuits:Stop/Turn
Signal Left* Yellow
Stop/Turn Signal
Right* Dark Green
Tail/Parking
Lamps** Brown
Reverse Lamps** Light Green
Battery Feed Red/Black
Ground White
Electric Trailer Brake Dark Blue
*If the vehicle is a cutaway with trailer
provisions, a 15 amp fuse will be shared
for both left/stop trailer turn and right/
stop trailer turn signals. However, the
cutaway lighting connector will have a
10 amp fuse for each signal.
**If the vehicle is a cutaway with trailer
provisions, a 15 amp fuse will be shared
for trailer park lamps and cutaway rear
lighting connector park lamps. Also, a
10 amp fuse will be shared for trailer
back-up lamps and cutaway rear lighting
connector back-up lamps. Heavy-Duty Trailer Wiring Harness Package
lf equipped, the trailer wiring harness, with
a seven-pin connector is mounted on the
trailer hitch.
1. Left Turn/Brake
2. Taillamps
3. Reverse Lamps
4. Battery Feed
5. Right Turn/Brake
6. Electric Brakes
7. Ground
Electric Brake Control Wiring Provisions
If the vehicle is not equipped with an
integrated trailer brake controller, and the
trailer has electric brakes, a trailer brake
controller needs to be installed on the
vehicle. The brake controller should be
installed by your dealer or a qualified
service center.
If equipped, wiring provisions for an
aftermarket electric trailer brake controller
are included with the vehicle as part of the
trailer wiring package. The harness contains
the following circuits:
Electric Trailer
Brakes Dark Blue
Battery Feed Red/White
Brake Apply Signal Light Blue
Ground Black
There are four blunt cut wires under the
floor carpeting in front of the brake pedal.
It will be necessary to have a technician
connect the 12-volt power to the engine
compartment fuse block.

GMC Savana Owner Manual (GMNA-Localizing-U.S./Canada-14583543) -
2021 - crc - 7/10/20
Driving and Operating 175
Refer to the aftermarket electric trailer brake
controller owner's manual to determine wire
color coding of the electric trailer brake
controller. The wire colors on the brake
controller may be different from the vehicle.
Trailer Lamps
Always check all trailer lamps are working at
the beginning of each trip, and periodically
on longer trips.
Turn Signals When Towing a Trailer
When properly connected, the trailer turn
signals will illuminate to indicate the vehicle
is turning, changing lanes, or stopping.
When towing a trailer, the arrows on the
instrument cluster will illuminate even if the
trailer is not properly connected or the bulbs
are burned out.
Tow/Haul Mode
Tow/Haul assists when pulling a heavy
trailer or a large or heavy load. For
instructions on how to enter Tow/Haul
mode, seeTow/Haul Mode 0145.
Tow/Haul Mode is designed to be most
effective when the vehicle and trailer
combined weight is at least 75% of the vehicle's Gross Combined Weight Rating
(GCWR). See
“Trailer Weight” underTrailer
Towing 0164.
Tow/Haul Mode is most useful when towing
a heavy trailer or carrying a large or
heavy load:
.through rolling terrain
.in stop-and-go traffic
.in busy parking lots
Operating the vehicle in Tow/Haul Mode
when lightly loaded or not towing will not
cause damage; however, it is not
recommended and may result in unpleasant
engine and transmission driving
characteristics and reduced fuel economy.
Trailer Sway Control (TSC)
Vehicles with StabiliTrak/Electronic Stability
Control (ESC) have a Trailer Sway Control
(TSC) feature. Trailer sway is unintended
side-to-side motion of a trailer while towing.
If the vehicle is towing a trailer and the TSC
detects that sway is increasing, the vehicle
brakes are selectively applied at each wheel,
to help reduce excessive trailer sway.
If TSC is enabled, the Traction Control
System (TCS)/StabiliTrak/ESC warning light
will flash on the instrument cluster. Reduce
vehicle speed by gradually removing your
foot from the accelerator. If trailer sway
continues, StabiliTrak/ESC can reduce engine
torque to help slow the vehicle. TSC will not
function if StabiliTrak/ESC is turned off. See
Traction Control/Electronic Stability Control
0 147.
{Warning
Trailer sway can result in a crash and in
serious injury or death, even if the
vehicle is equipped with TSC.
If the trailer begins to sway, reduce
vehicle speed by gradually removing your
foot from the accelerator. Then pull over
to check the trailer and vehicle to help
correct possible causes, including an
improperly or overloaded trailer,
(Continued)

GMC Savana Owner Manual (GMNA-Localizing-U.S./Canada-14583543) -
2021 - crc - 7/10/20
176 Driving and Operating
Warning (Continued)
unrestrained cargo, improper trailer hitch
configuration, or improperly inflated or
incorrect vehicle or trailer tires. See
Towing Equipment0172 for trailer
ratings and hitch setup recommendations.
Trailer Tires
Special Trailer (ST) tires differ from vehicle
tires. Trailer tires are designed with stiff
sidewalls to help prevent sway and to
support heavy loads. These features can
make it difficult to determine if the trailer
tire pressures are low only based on a visual
inspection.
Always check all trailer tire pressures before
each trip when the tires are cool. Low trailer
tire pressure is a leading cause of trailer tire
blow-outs.
Trailer tires deteriorate over time. The trailer
tire sidewall will show the week and year
the tire was manufactured. Many trailer tire
manufacturers recommend replacing tires
more than six years old. Overloading is another leading cause of
trailer tire blow-outs. Never load your trailer
with more weight than the tires are
designed to support. The load rating is
located on the trailer tire sidewall.
Always know the maximum speed rating for
the trailer tires before driving. This may be
significantly lower than the vehicle tire
speed rating. The speed rating may be on
the trailer tire sidewall. If the speed rating is
not shown, the default trailer tire speed
rating is 105 km/h (65 mph).
Conversions and Add-Ons
Add-On Electrical Equipment
{Warning
The Data Link Connector (DLC) is used for
vehicle service and Emission Inspection/
Maintenance testing. See
Malfunction
Indicator Lamp (Check Engine Light) 076.
A device connected to the DLC —such as
an aftermarket fleet or driver-behavior
tracking device —may interfere with
vehicle systems. This could affect vehicle (Continued)
Warning (Continued)
operation and cause a crash. Such devices
may also access information stored in the
vehicle’s systems.
Caution
Some electrical equipment can damage
the vehicle or cause components to not
work and would not be covered by the
vehicle warranty. Always check with your
dealer before adding electrical equipment.
Add-on equipment can drain the vehicle's
12-volt battery, even if the vehicle is not
operating.
The vehicle has an airbag system. Before
attempting to add anything electrical to the
vehicle, see Servicing the Airbag-Equipped
Vehicle 044 and
Adding Equipment to the Airbag-Equipped
Vehicle 045.

GMC Savana Owner Manual (GMNA-Localizing-U.S./Canada-14583543) -
2021 - crc - 7/10/20
Vehicle Care 187
How to Check Automatic Transmission
Fluid
Because this operation can be difficult, it is
recommended to have this check done at
your dealer, which can monitor the
transmission temperature. The transmission
fluid level increases with temperature. To
obtain a highly accurate fluid level check,
the transmission temperature must be
measured.
If it is decided to check the fluid level, be
sure to follow all the instructions here, or a
false reading on the dipstick may occur.
Caution
Too much or too little fluid can damage
the transmission. Too much can mean
that some of the fluid could come out
and fall on hot engine parts or exhaust
system parts, starting a fire. Too little
fluid could cause the transmission to
overheat. Be sure to get an accurate
reading if checking the transmission fluid.
Wait at least 30 minutes with the engine
off, before checking the transmission fluid
level if the vehicle has been driven:
.In hot weather, when outside
temperatures are above 32 °C (90 °F).
.The vehicle is heavily loaded.
.At high speed for quite a while in hot
weather.
.In heavy traffic and hot weather.
.While pulling a trailer.
After driving under these conditions, a hot
check can be performed. The fluid should be
hot, which is 71 °C to 93 °C (160 °F to
200 °F).
A cold fluid level check can be performed
after the vehicle has been sitting for eight
hours or more with the engine off, but this
is used only as a reference. Let the engine
run at idle for five minutes if the outside
temperature is between 15 °C to 32 °C (60 °F
to 90 °F). Should the fluid level be low
during this cold check, the fluid must be
checked warm or hot before adding fluid.
If the outside temperature is colder than 15 °
C (60 °F) or hotter than 32 °C (90 °F), a cold
check cannot be performed.
A warm fluid level check can be performed
by driving the vehicle under lightly loaded
conditions and outside temperatures
between 10 °C to 27 °C (50 °F to 80 °F). The
vehicle should be driven for at least 24 km (15 mi) before performing a warm check.
Checking the fluid warm or hot will give a
more accurate reading of the fluid level than
a cold check.
Because the vehicle is equipped with a
high-efficiency air-to-oil cooler, the
transmission fluid temperature may not
reach the required hot fluid level checking
temperature under normal lightly loaded
driving vehicle conditions.
Checking the Fluid Level
Prepare the vehicle:
1. Park the vehicle on a level place. Keep the engine running.
2. With the parking brake applied, place the shift lever in P (Park).
3. With a foot on the brake pedal, move the shift lever through each gear range,
pausing for about three seconds in each
range. When M is reached, move the
selector from M1 through M3. Then,
position the shift lever in P (Park).
4. Let the engine run at idle for two minutes or more.
Then, without shutting off the engine, use
the steps that follow.

GMC Savana Owner Manual (GMNA-Localizing-U.S./Canada-14583543) -
2021 - crc - 7/10/20
198 Vehicle Care
.Normal brake lining wear. When new
linings are installed, the fluid level goes
back up.
.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 077.
Brake fluid absorbs water over time. Replace
brake fluid at the specified intervals to
prevent increased stopping distance. See
Maintenance Schedule 0249.
Checking Brake Fluid
Check brake fluid by looking at the brake
fluid reservoir. See Engine Compartment
Overview 0180.
The fluid level should be above MIN. If it is
not, have the brake hydraulic system
checked to see if there is a leak. After work is done on the brake hydraulic
system, make sure the level is above MIN
but not over the MAX mark.
What to Add
Use only GM approved DOT 3 brake fluid
from a clean, sealed container. See
Recommended Fluids and Lubricants
0255.
{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.

GMC Savana Owner Manual (GMNA-Localizing-U.S./Canada-14583543) -
2021 - crc - 7/10/20
Vehicle Care 203
1. Use a small tool to unlatch the outboardclip on the lamp by pushing inboard and
prying the lamp assembly forward.
2. Remove the lamp from the grille.
3. Turn the bulb socket counterclockwise one-quarter turn and remove it from the
lamp assembly.
4. Remove the bulb from the socket by pulling it straight out.
5. Replace the bulb.
6. Turn the bulb socket clockwise to reinstall it in the lamp assembly.
7. Reinstall the lamp assembly into the grille until the outboard clip snaps into
place.
Taillamps
To replace a taillamp/turn signal lamp or
back-up lamp bulb:
1. Remove the two inboard nuts from theinside of the taillamp assembly.
2. The third nut (3) is under the appliquepiece (2) above the lamp. Remove the
two inboard applique nuts. Pull the
applique (2) straight rearward slightly to
clear the studs. Then rotate the
applique (2) just far enough to gain
access to the outer push pins (1).
3. Carefully disconnect the push pins (1) from the applique bracket.
4. Remove the third nut (3) from the upper outboard side of the lamp.
5. Remove the taillamp assembly from the vehicle.