Chevrolet 2011 Volt Owner's Manual page 390

The vehicle is equipped with an
electric power steering system.
No fluid or general maintenance
is required.
When adding windshield washer
fluid to the vehicle, be sure to read
the manufacturer's instructions
before use. If operating the vehicle
in an area where the temperature
may fall below freezing, use a fluid
that has sufficient protection against
freezing.
The WASHER FLUID LOW ADD
FLUID message will appear on
the Driver Information Center
(DIC) when the fluid level is low.
See
for more information.
Open the cap with the washer
symbol on it. Add washer fluid
until the tank is full. See
for reservoir location.