Voltmeter Gauge - GMC 2011 Sierra Denali Owner's Manual

5-18 Instruments and Controls

Voltmeter Gauge

When the engine is not running, but
the ignition is on, this gauge shows
the battery's state of charge in
DC volts.
When the engine is running, the
gauge shows the condition of the
charging system. The gauge can
transition from a higher to lower or a
lower to higher reading. This is
normal. Readings between the low
and high warning zones indicate the
normal operating range.
The voltmeter gauge may also read
lower when in fuel economy mode.
This is normal.
Readings in the low warning zone
can occur when a large number of
electrical accessories are operating
in the vehicle and the engine is left
at an idle for an extended period.
This condition is normal since the
charging system is not able to
provide full power at engine idle.
As engine speeds are increased,
this condition should correct itself as
higher engine speeds allow the
charging system to create maximum
power.
The vehicle can only be driven for a
short time with the reading in either
warning zone. If the vehicle must be
driven, turn off all unnecessary
accessories.
Readings in either warning zone
indicate a possible problem in the
electrical system. Have the vehicle
serviced as soon as possible.