GMC Savana Owner Manual (GMNA-Localizing-U.S./Canada-13882574) -
2020 - CRC - 11/1/19
200 Driving and Operating
Maintenance when Trailer
Towing
The vehicle needs service more
often when used to tow trailers. See
Maintenance Schedule0304. It is
especially important to check the
automatic transmission fluid, engine
oil, axle lubricant, belts, cooling
system, and brake system before
and during each trip.
Check periodically that all nuts and
bolts on the trailer hitch are tight.
Engine Cooling when Trailer
Towing
The cooling system may temporarily
overheat during severe operating
conditions. See Engine Overheating
0 234.
Trailer Towing
If equipped with a diesel engine,
see the Duramax diesel
supplement.
Caution
Towing a trailer improperly can
damage the vehicle and result in
costly repairs not covered by the
vehicle warranty. To tow a trailer
correctly, follow the directions in
this section and see your dealer
for important information about
towing a trailer with the vehicle.
Trailering is different than just
driving the vehicle by itself.
Trailering means changes in
handling, acceleration, braking,
durability, and fuel economy.
Successful, safe trailering takes
correct equipment, and it has to be
used properly. The following information has many
time-tested, important trailering tips
and safety rules. Many of these are
important for your safety and that of
your passengers. Read this section
carefully before pulling a trailer.
Trailer Weight
{Warning
Never exceed the towing capacity
for your vehicle.
Safe trailering requires monitoring
the weight, speed, altitude, road
grades, outside temperature,
dimensions of the front of the trailer,
and how frequently the vehicle is
used to tow a trailer.
GMC Savana Owner Manual (GMNA-Localizing-U.S./Canada-13882574) -
2020 - CRC - 11/1/19
Driving and Operating 201
Trailering Weight Ratings
When towing a trailer, the combined
weight of the vehicle, vehicle
contents, trailer, and trailer contents
must be below all of the maximum
weight ratings for the vehicle,
including:
.GCWR: Gross Combined Weight
Rating
. GVWR: Gross Vehicle Weight
Rating
. Maximum Trailer Weight Rating
. GAWR-RR: Gross Axle Weight
Rating-Rear
. Maximum Trailer Tongue Weight
Rating
See “Weight-Distributing Hitch
Adjustment” underTowing
Equipment 0207 to determine if
equalizer bars are required to obtain
the maximum trailer weight rating. See
“Trailer Brakes” underTowing
Equipment 0207 to determine if
brakes are required based on your
trailer's weight.
The only way to be sure the weight
is not exceeding any of these
ratings is to weigh the tow vehicle
and trailer combination, fully loaded
for the trip, getting individual
weights for each of these items.
{Warning
You and others could be seriously
injured or killed if the trailer is too
heavy or the trailer brakes are
inadequate for the load. The
vehicle may be damaged, and the
repairs would not be covered by
the vehicle warranty.
Only tow a trailer if all the steps in
this section have been followed.
Ask your dealer for advice and
information about towing a trailer.
Gross Combined Weight
Rating (GCWR)
GCWR is the total allowable weight
of the completely loaded vehicle
and trailer including any fuel,
passengers, cargo, equipment, and
accessories. Do not exceed the
GCWR for your vehicle. The GCWR
for the vehicle is on the Tow Rating
Chart following.
To check that the weight of the
vehicle and trailer are within the
GCWR for the vehicle, follow these
steps:
1. Start with the curb weight from the Tow Rating Chart.
2. Add the weight of the trailer loaded with cargo and ready
for the trip.
3. Add the weight of all passengers.
4. Add the weight of all cargo in the vehicle.
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
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 241
TAMPERING WITH NOISE
CONTROL SYSTEM
PROHIBITED
Federal law prohibits the following
acts or the causing thereof:1. The removal or rendering inoperative by any person,
other than for purposes of
maintenance, repair,
or replacement, of any device
or element of design
incorporated into any new
vehicle for the purpose of noise
control prior to its sale or
delivery to the ultimate
purchaser or while it is in
use; or
2. The use of the vehicle after such device or element of
design has been removed or
rendered inoperative by any
person.
Among those acts presumed to
constitute tampering are the acts
listed below. 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. Fuel Operated Heater (FOH) -
Diesel Engine:
.
Removal of the muffler.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).
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