System and method of controlling the activation of a vacuum-driven actuator

A method of controlling a vacuum-driven actuator in a vehicle having a manifold and a vacuum reservoir for storing available vacuum, the method comprising:

• determining the actuator is to be actuated;
• determining an amount of vacuum available to actuate the actuator;
• determining whether the available vacuum is sufficient to actuate the actuator;
• actuating the actuator only when the available vacuum is sufficient;
• and
• preventing actuation of the actuator when the available vacuum is insufficient;
• wherein determining the amount of vacuum available further comprises:
• determining a manifold pressure;
• and
• using the determined manifold pressure to determine a reservoir pressure.

An actuator control system in a vehicle, the system comprising:

• a switching monitor operable to determine when the actuator is to be actuated;
• a vacuum level module operable to determine an amount of vacuum available to actuate the actuator;
• a switch operable to actuate the actuator;
• and
• a switch controller operable to determine whether the available vacuum is sufficient to actuate the actuator, and to actuate the switch only when the available vacuum is sufficient to actuate the actuator.