Vacuum sensors: monitoring a brake booster

Useful to know

The vacuum sensor in the Bosch described system monitors the vacuum in the brake booster. This allows control of the electric vacuum pump and supports functions such as start-stop. It is about a specific type of boost, not about all possible braking systems. [1]

The vacuum in the amplifier is a different magnitude from the hydraulic pressure in the brake loop. Mixing them leads to vague descriptions of the "no pressure" type that do not indicate which process is being observed.

If there is a change in the feel of the pedal or a warning message, follow the vehicle's directions for safe operation and inspection. The sensor is part of the feedback, but the symptom does not determine the cause itself. It is not enough to know that the car has a vacuum pump; the specific configuration and the data from its diagnosis are important.