A strategy controls alternate anti-vibration modes in a switchable
powertrain mount using vehicle operational status sensors and
pre-selected thresholds. The switchable mount modes can include engine
off-idle and an idle mode. Vehicle sensors and pre-selected thresholds
can determine whether the engine is off-idle, or running in idle mode,
whether the engine will likely remain in idle mode. From these
determinations, the controller can command the switchable mount to engine
idle mode when the controller determines the engine is in idle mode and
will likely remain in idle mode. The switching means for the switchable
mount can use a three-way vacuum solenoid valve (VSV), or a mechanical or
electrical switch. In the case of the VSV configuration, the VSV is
communicatively attached to the controller, a vacuum line connects the
VSV to the switchable mount, and a second vacuum line connects the VSV to
an engine intake manifold.