Vacuum Pump Assembly: Notes
WARNING: This page is about a different car, the 2000 Land Rover Range Rover, 2000 Land Rover Discovery, 1999 Land Rover Range Rover, and 1999 Land Rover Discovery. However, it is still accessible from the selected car via links, so may be relevant.
NOTE:
Vacuum dump valve is normally open. Vacuum dump valve is permanently grounded through the brakelight bulbs. When cruise control is activated, ECU energizes dump valve, which closes. When brake pedal is pressed, voltage used to illuminate the brakelights cancels dump valve ground and valve opens. When dump valve opens, cruise control actuator vacuum is released and throttle is released.