
Chevrolet VOLT Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
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Driving and Operating 177
Mode mainly during highway or high
speed driving to maximize both EV
miles and fuel efficiency.
Hold Mode is only available when
the vehicle is in Electric Mode. This
mode places the remaining battery
charge into a reserve for the driver
to use as desired. Selecting this
mode transitions the vehicle to
Extended Range Mode to maintain
the battery charge reserve.
Upon exiting Hold Mode, the
reserved battery charge becomes
available again and the vehicle
returns to Electric Mode. If the
transition is from Hold Mode directly
to Mountain Mode, the electric
range displayed adjusts for the
Mountain Mode charge reserve.
Hold Mode will not change normal
vehicle acceleration or braking
performance.
Press MODE to select Hold Mode.
Press MODE again to return to
Normal Mode and it becomes active
after three seconds.Each time the vehicle is started, it
will return to Normal Mode.
Out of Fuel/Engine
Unavailable
If the vehicle runs out of fuel, or the
engine will not start due to a
malfunction, the vehicle can
continue to be driven in Electric
Mode until the current charge is
depleted. The vehicle will have less
responsive acceleration. Driver
Information Center (DIC) messages
indicate reduced propulsion power,
that the engine is not available, and
the need for fuel or service.
Once the vehicle is refueled, or the
malfunction is corrected, the engine
will start the next time the vehicle is
turned on to perform a self test, and
DIC messages will not be displayed.
Once the engine starts successfully,
normal operation will continue in
either Electric or Extended Range
Mode. The engine may stop running
after the self test is completed,
based on the current mode of
operation.
Maintenance Modes
Engine Maintenance Mode (EMM)
EMM runs the engine to keep it in
good working condition after
approximately six weeks of no or
very limited engine operation. EMM
will force the engine to run, even if
there is a charge to power the
vehicle.
When EMM is needed, the EMM
notification will display.
If Start is selected, EMM will begin.
The engine will not start until after a
short delay once shifted into
D (Drive). The engine will run for a
set amount of time without turning

Chevrolet VOLT Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
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178 Driving and Operating
off. During EMM, a DIC message
displays to show the
EMM percentage complete.
If More Info is selected, a pop-up
will show describing the Engine
Maintenance procedure. There will
be an option to Start or an option to
Postpone. Postpone will allow EMM
to be delayed for up to one day and
the EMM notification will re-appear
when the vehicle is next started.
If the EMM request was delayed for
one day, EMM will automatically
start the engine at the next vehicle
start, and a notification will display
stating that EMM is starting
maintenance. A More Info button will
also be available on the notification
which, when pressed, provides an
explanation of Engine Maintenance.The engine will not start until after a
short delay once shifted into
D (Drive).
If the vehicle is shut off during EMM,
it will restart the next time the
vehicle is driven and a notification
will display showing that
maintenance is being resumed now.
A message displays to indicate that
EMM is active and a notification will
display showing that maintenance is
being resumed now.
If EMM is required and the fuel level
is low, EMM may eventually empty
the fuel tank if fuel is not added.
This will result in reduced, or no
power. An adequate fuel level must
be maintained in the vehicle to keep
it operational. See
Propulsion Power
Messages 0136.
Fuel Maintenance Mode (FMM)
FMM tracks average fuel age. Old
fuel can cause engine problems.
If low engine usage causes average
fuel age to exceed approximately
one year, FMM will run the engine to
use up the old fuel. The engine will
run until enough fresh fuel is added
to bring the average fuel age into an
acceptable range. Allowing more old
fuel to be used up by FMM and
adding a larger amount of fresh fuel
will maximize the length of time
before another fuel maintenance
mode is needed. During FMM the
engine may turn on and off.

Chevrolet VOLT Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
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Driving and Operating 179
When FMM is needed, the FMM
notification will display.
If Start is selected, FMM will begin.
The engine will not start until after a
short delay once shifted into
D (Drive). FMM will automatically
continue at each vehicle start until
fresh fuel is added.
If More Info is selected, a pop-up
will show describing the Fuel
Maintenance procedure. There will
be an option to Start or an option to
Postpone. Postpone will allow FMM
to be delayed for up to one day and
the FMM notification will re-appear
when the vehicle is next started.
If the FMM request was delayed for
one day, FMM will start at the next
vehicle start and display the FMM
Notification screen on the
infotainment display. The engine will
not start until after a short delay
once shifted into D (Drive).
A More Info button will also be
available on the notification which,
when pressed, provides an
explanation of Fuel Maintenance.
If the vehicle is shut off during FFM,
it will restart the next time the
vehicle is driven and a notification
will display showing that
maintenance is being resumed now.
If FMM is required and the fuel level
is low, FMM may eventually empty
the fuel tank if fuel is not added.
This will result in reduced, or no
power. An adequate fuel level must
be maintained in the vehicle to keep
it operational. SeePropulsion Power
Messages 0136. After FMM has
run it is recommended to fill the
fuel tank.

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Driving and Operating 233
Warning (Continued)
.Bring the fill nozzle in
contact with the inside of
the fill opening before
operating the nozzle.
Contact should be
maintained until the filling is
complete.
. Do not smoke while
pumping fuel.
. Avoid using electronic
devices.
Trailer Towing
General Towing
Information
{Warning
Never tow a trailer with your
vehicle. It was not designed or
intended to tow a trailer.
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) 0114.
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.

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238 Vehicle Care
Warning (Continued)
High voltage components are
identified by labels. Do not
remove, open, take apart,
or modify these components.
High voltage cable or wiring has
orange covering. Do not probe,
tamper with, cut, or modify high
voltage cable or wiring.
{Warning
It can be dangerous to work on
your vehicle if you do not have
the proper knowledge, service
manual, tools, or parts. Always
follow owner’s manual procedures
and consult the service manual
for your vehicle before doing any
service work. If doing some of your own service
work, use the proper service
manual. It tells you much more
about how to service the vehicle
than this manual can. To order the
proper service manual, see
Publication Ordering Information
0
345.
This vehicle has an airbag system.
Before attempting to do your own
service work, see Airbag System
Check 079.
The vehicle is equipped with remote
start. Open the hood before
performing any service work to
prevent remote starting the vehicle
accidentally. See Remote Start
0 38.
Keep a record with all parts receipts
and list the mileage and the date of
any service work performed. See
Maintenance Records 0331.
Caution
Even small amounts of
contamination can cause damage
to vehicle systems. Do not allow
contaminants to contact the fluids,
reservoir caps, or dipsticks.
Hood
To open the hood:
1. Turn the vehicle off before opening the hood. If the vehicle
is on, the engine will start when
the hood is opened.
See Electric Mode 0174 and
Extended Range Mode 0174.

Chevrolet VOLT Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
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Vehicle Care 245
when to change to vary greatly. It is
possible an air filter change may not
be indicated for up to four years.
When the "Replace at Next Oil
Change" message displays, the
engine air filter should be replaced
at the time of the next engine oil
change. When the "Replace Engine
Air Filter Now" message displays,
the engine air filter should be
replaced as soon as possible. Reset
the engine air filter life system after
the engine air filter is replaced. See
your dealer for service and to reset
the system.
How to Reset Engine Air Filter
Life System
Reset the system whenever the
engine air filter is replaced so that
the system can calculate the next
engine air filter change.
To reset:1. Place the vehicle in P (Park).
2. Select Engine Air Filter Life on the DIC menu. See Driver
Information Center (DIC) 0133. 3. Press
pto move to the Reset/
Disable display area. Select
Reset then press
V. Then
press Yes to confirm the reset.
4. 100% Air Filter Life will be displayed when the Engine Air
Filter Life System is
successfully reset.
Engine Air Cleaner/Filter
The engine air cleaner/filter is in the
engine compartment on the
passenger side of the vehicle. See
Engine Compartment Overview
0240.
When to Inspect the Engine Air
Cleaner/Filter
.
For intervals on changing and
inspecting the engine air filter,
see Maintenance Schedule
0 321.
. If equipped with Engine Air Filter
Life System, see Engine Air
Filter Life System 0244. .
If driving in very dusty areas,
follow the engine air filter
inspecting and changing
intervals, see Maintenance
Schedule 0321.
How to Inspect the Engine Air
Filter
Do not start the engine or have the
engine running with the engine air
cleaner/filter housing open. Before
removing the engine air cleaner/
filter, make sure that the engine air
cleaner/filter housing and nearby
components are free of dirt and
debris. Remove the engine air
cleaner/filter. Lightly tap and shake
the engine air cleaner/filter (away
from the vehicle), to release loose
dust and dirt. Inspect the engine air
cleaner/filter for damage, and
replace if damaged. Do not clean
the engine air cleaner/filter or
components with water or
compressed air.
To inspect or replace the air filter:
1. Open the hood. See Hood
0 238.

Chevrolet VOLT Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
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Vehicle Care 247
{Warning
An underhood electric fan can
start up even when the engine is
not running and can cause injury.
Keep hands, clothing, and tools
away from any underhood
electric fan.
If the coolant inside the coolant
surge tank is boiling, do not do
anything else until it cools down.
The vehicle should be parked on a
level surface.
The coolant level should be up to
the cold fill line. If it is not, there
might be a leak at the radiator
hoses, heater hoses, radiator, water
pump, or somewhere else in the
cooling system.
{Warning
Do not touch heater or radiator
hoses, or other engine parts.
They can be very hot and can (Continued)
Warning (Continued)
burn you. Do not run the engine if
there is a leak; all coolant could
leak out. That could cause an
engine fire and can burn you. Fix
any leak before driving the
vehicle.
If there seems to be no leak, with
the engine on, check to see if the
cooling fans are running. If the
engine is overheating, the fans
should be running. If they are not,
the vehicle needs service. Turn off
the vehicle.
Engine Coolant
The engine cooling system in the
vehicle is filled with GM Premix
DEX-COOL engine coolant. See
Recommended Fluids and
Lubricants 0329. The coolant
requires changing at certain
intervals. See Maintenance
Schedule 0321. The following explains the cooling
system and how to check and add
coolant when it is low. If there is a
problem with engine overheating,
see
Engine Overheating 0252.
What to Use
{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.
Use GM Premix DEX-COOL engine
coolant. This mixture:
. Gives freezing protection down
to−37 °C (−34 °F), outside
temperature.
. Gives boiling protection up to
129 °C (265 °F), engine
temperature.

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250 Vehicle Care
Caution
If the pressure cap is not tightly
installed, coolant loss and engine
damage may occur. Be sure the
cap is properly and tightly
secured.
Cooling System (High
Voltage Battery)
During vehicle operation and also
during charging, the high voltage
battery cells in the vehicle are kept
within a normal operating
temperature range. If the high
voltage battery cell temperature
rises above the normal operating
temperature range, the battery
cooling system turns on the air
conditioning compressor and cools
the coolant until the correct battery
cell temperature is reached. If the
high voltage battery cell temperature
falls below the normal operating
temperature range, a high voltage
heater, located in the battery, heats
the coolant until the correct battery
cell temperature is reached.During high voltage battery system
cooling, you may feel temperature
changes at the air vents due to the
extra load on the system.
What to Use
The high voltage battery coolant
reservoir in the vehicle is filled with
GM Premix DEX-COOL engine
coolant. See
Recommended Fluids
and Lubricants 0329. If using this
mixture, nothing else needs to be
added.
The coolant needs to be replaced at
the appropriate interval. See
Maintenance Schedule 0321.
Checking Coolant
The vehicle must be on a level
surface when checking the coolant
level.
The high voltage battery coolant
reservoir is located in the engine
compartment. See Engine
Compartment Overview 0240.
1. High Voltage Battery
Coolant Reservoir
2. Power Electronics Coolant Reservoir
Check to see if coolant is visible in
the high voltage battery coolant
reservoir (1). If coolant is visible but
the coolant level is below the cold
fill line on the side of the reservoir,
there could be a leak in the cooling
system.
The high voltage battery cooling
system supports the operation of
sensitive electronics that are critical
to vehicle operation.