Theory Of Operation

The electronically controlled Vacuum Pump system is installed to provide supplemental vacuum to the Brake Booster when the engine vacuum supply is low. This system maintains a consistent brake pedal feel under all driving conditions. The Vacuum Pump is connected to the engine and the Brake Booster through a series of hoses and one-way flow check valves. A Vacuum Pressure Sensor mounted in the Brake Booster is hard wired to the Anti-lock Brake System (ABS) Module. The Vacuum Pressure Sensor signal information is then sent to the Powertrain Control Module (PCM) over the CAN Bus. The PCM energizes the Vacuum Pump Relay with a Low Side Driver (LSD) to control the Vacuum Pump operation and maintain the Brake Booster vacuum.