trailer GMC SAVANA 2020 Owner's Guide

GMC Savana Owner Manual (GMNA-Localizing-U.S./Canada-13882574) -
2020 - CRC - 11/1/19
Driving and Operating 209
Trailer Wiring Harness
Basic Trailer Wiring
If the vehicle is not equipped with a
trailer connector on the rear bumper,
a seven-wire trailering harness is
tied to the vehicle’s frame. The
harness requires the installation of a
trailer connector, which is available
through your dealer.
Use only a round, seven-wire
connector with flat blade terminals
meeting SAE J2863 specifications
for proper electrical connectivity.
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

GMC Savana Owner Manual (GMNA-Localizing-U.S./Canada-13882574) -
2020 - CRC - 11/1/19
210 Driving and Operating
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.
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, see
Tow/Haul
Mode 0174.
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 ”under Trailer
Towing 0200.
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

GMC Savana Owner Manual (GMNA-Localizing-U.S./Canada-13882574) -
2020 - CRC - 11/1/19
Driving and Operating 211
sway is increasing, the vehicle
brakes are selectively applied at
each wheel, to help reduce
excessive trailer sway. If equipped
with the Integrated Trailer Brake
Control (ITBC) system, and the
trailer has an electric brake system,
StabiliTrak/ESC may also apply the
trailer brakes.
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. SeeTraction Control/Electronic
Stability Control 0177.
{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, unrestrained
cargo, improper trailer hitch
configuration, or improperly
inflated or incorrect vehicle or
trailer tires. See Towing
Equipment 0207 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.

GMC Savana Owner Manual (GMNA-Localizing-U.S./Canada-13882574) -
2020 - CRC - 11/1/19
212 Driving and Operating
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. SeeMalfunction Indicator
Lamp (Check Engine Light) 092.
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
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 053 and
Adding Equipment to the
Airbag-Equipped Vehicle 054.

GMC Savana Owner Manual (GMNA-Localizing-U.S./Canada-13882574) -
2020 - CRC - 11/1/19
Vehicle Care 225
suspected, use the following
procedures to check the fluid level.
However, if there is a large leak, it
may be necessary to have the
vehicle towed to a dealer and have
it repaired before driving the vehicle
further.
Change the fluid and filter at the
intervals listed inMaintenance
Schedule 0304, and be sure to use
the transmission fluid listed in
Recommended Fluids and
Lubricants 0312.
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

GMC Savana Owner Manual (GMNA-Localizing-U.S./Canada-13882574) -
2020 - CRC - 11/1/19
Vehicle Care 235
If No Steam is Coming from
the Engine Compartment
If an engine overheat warning is
displayed but no steam can be 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.
If the overheat warning is displayed
with no sign of steam: 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.
3. When it is safe to do so, pull off the road, shift to P (Park) or
N (Neutral) and let the
engine idle.
If the engine coolant temperature
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,
push down the accelerator until the
engine speed is about twice as fast
as normal idle speed for at least
three minutes while parked. If the
warning is still on, turn off the
engine until it cools down.
If the decision is made not to lift the
hood, get service help right away.
Engine Fan
The vehicle has a clutched engine
cooling fan. When the clutch is
engaged, the fan spins faster to
provide more air to cool the engine.
In most everyday driving conditions,
the fan is spinning slower and the
clutch is not fully engaged. This
improves fuel economy and reduces
fan noise. Under heavy vehicle
loading, trailer towing, and/or high
outside temperatures, the fan speed
increases as the clutch more fully
engages, so an increase in fan
noise may be heard. This is normal
and should not be mistaken as the
transmission slipping or making
extra shifts. It is merely the cooling
system functioning properly. The fan
will slow down when additional
cooling is not required and the
clutch partially disengages.
This fan noise may be heard when
starting the engine. It will go away
as the fan clutch partially
disengages.
Power Steering Fluid

GMC Savana Owner Manual (GMNA-Localizing-U.S./Canada-13882574) -
2020 - CRC - 11/1/19
Vehicle Care 249
The vehicle may not be equipped
with all of the fuses, relays, and
features shown.Fuses
Usage
1 ABS motor
2 ABS module Fuses
Usage
3 Right trailer stoplamp/Turn
signal lamp
4 –
5 –
6 Fuel system control module/Ignition
7 Body control module 5
8 Body control module 7
9 Body control module 4
10 Instrument cluster 11 Trailer wiring
12 –
13 Interior rear vision camera module
14 Windshield washer
16 Horn
17 Transmission
18 A/C

GMC Savana Owner Manual (GMNA-Localizing-U.S./Canada-13882574) -
2020 - CRC - 11/1/19
250 Vehicle Care
FusesUsage
19 Engine control module battery
20 Left stop/turn cutaway lamp
21 Left stop/turn trailer lamp
22 Right stop/turn cutaway lamp
23 –
24 Fuel pump
25 Auxiliary power outlet
26 Body control module 3
27 Special equipment option
28 Airbag
29 Steering wheel sensor
30 Engine control module/Ignition Fuses
Usage
31 Transmission control module
Ignition
32 Transmission control module 1
battery
33 Rear parking aid module
34 –
35 –
36 Fuel system control module battery
41 Transmission control module 2,
battery signal
42 Trailer wiring
43 –
44 Starter solenoid
45 Engine control module, powertrain
signal 2
46 DC-AC inverter
47 – Fuses
Usage
51 Left high-beam headlamp
52 Right high-beam headlamp
53 Left low-beam headlamp
54 Right low-beam headlamp
55 Wipers
56 Canister vent solenoid
58 Body control module 2
59 Body control module 1
61 Engine oil solenoid
62 O2 sensor 2
63 –
64 Mass airflow/ Canister vent
65 Ignition coils/ injectors - odd

GMC Savana Owner Manual (GMNA-Localizing-U.S./Canada-13882574) -
2020 - CRC - 11/1/19
Vehicle Care 251
FusesUsage
66 Daytime running lamps 2
67 Daytime running lamps 1
68 Auxiliary stoplamps
69 External power for trailer
70 Upfitter stoplamps
71 Fuel heater/ FlexFuel sensor
72 Body control module 6
73 Lighter/Data link connector
74 Front blower
75 Engine control module
76 –
77 O2 sensor 1
78 Engine control module, powertrain
signal 1 Fuses
Usage
79 Ignition coils/ injectors - even
Relays Usage
15 Run/Crank
37 –
38 Fuel pump
39 Crank
40 A/C compressor
48 –
49 Powertrain
50 –
57 –
60 – Auxiliary Fuse Block
This component is near the fuse
block in the engine compartment
Fuses Usage
MR-1 Upfitter 1
MR-2 Upfitter 2
MR-3 Upfitter power control
Relays Usage
MR Rel 1 Upfitter 1
MR Rel 2 Upfitter 2

GMC Savana Owner Manual (GMNA-Localizing-U.S./Canada-13882574) -
2020 - CRC - 11/1/19
Vehicle Care 253
The vehicle may not be equipped
with all of the fuses, relays, and
features shown.Mini-Fuses Usage
F1 –
F2 Steering wheel sensor
F3 Auxiliary parking lamps
F4 Front parking lamps
F5 Trailer parking lamps
F6 Upfitter/Parking lamps
F7 Right rear parking lamp
F8 Left rear parking lamp
F9 Exterior rear mirror switch/ Door
lock-unlock control
upfitter/Front
camera module Mini-Fuses Usage
F10 Airbag/Automatic occupant sensing
F11 –/OnStar
F12 ECM batt V6 gas
F13 HVAC 2
F14 HVAC 1
F15 Reflected LED display
F16 Upfitter aux 1/Gas ambulance
F17 Heated outside mirrors
F18 Rear window defogger
F19 Compass
F20 Radio/Chime/ SiriusXM satellite
radio
F21 Remote function actuator/Tire
pressure monitor Mini-Fuses Usage
F22 Ignition switch/ Discrete logic
ignition sensor
F23 Instrument cluster
F24 –
F25 HVAC control
F26 Auxiliary/Trailer reverse lamps
F27 Reverse tail lamps
F28 Upfitter 2/Reading lamps/Ambulance
F29 Rear blower
F30 Upfitter/Courtesy lamps
F31 Front door lock
F32 Rear door lock
F33 Cargo door unlock
F34 Passenger door unlock
F35 Rear passenger door unlock
F36 Driver door lock