What is the Brake Booster Vacuum Sensor all about?

Brake boosters or power brakes use a vacuum to generate the additional force needed for efficient braking. The internal combustion engine in cars provide the vacuum with what it needs for the brake boosters to function.

Most internal combustion engines come with an engine control system that senses situations where there is low workload and the engine will not operate on all eight cylinders. This system deactivates some of the cylinders for fuel conservation in the Displacement on Demand or DOD mode. However, an engine in the DOD mode might not provide sufficient vacuum to the brake booster.

The brake booster vacuum sensor is a single chip device that manufacturers fit onto the electrical control unit of the brake booster. This device monitors the vacuum in the brake booster and ensures that there is a sufficient vacuum. If the vacuum levels fall below optimum levels, the brake booster vacuum sensor sends a signal to the engine and deactivates the DOD mode. Once activated, the engine can once again create sufficient vacuum for the brake boosters to function.

The brake booster vacuum sensor might also send a signal to the brake booster vacuum pump and activate it to raise the levels of vacuum. In case there is a leak in the vacuum air line or pipe, the sensor detects this as well.

Keep in mind:

• If the brake booster vacuum sensor is not operating properly, it will not allow the engine to transition from the DOD to the activated mode. The engine could fluctuate between the two modes. Thus, there are low levels of vacuum.
• The supplemental brake assist system in your car works to correct the vacuum issue. If it is unsuccessful, you will see the Service Brake Booster message on the dashboard.

Our recommendation:

It is advisable to keep your power brakes or brake booster working in perfect condition for effective braking when driving on the road. If you see the Reduced Brake Power and Service Brake Booster indicators on your dashboard, you should book an appointment with one of our expert mechanics right away. These indicators are a signal that the brake booster vacuum sensor is not working and is unable to correct the vacuum issue in the brake booster. Have the entire brake booster system checked if you need to use excessive force when braking.

What common symptoms indicate you may need to replace the Brake Booster Vacuum Sensor?

• Reduced Brake Power message comes on the dashboard
• Service Brake Booster message light comes on

How important is this service?

Not having an efficient and properly working braking system can be a safety hazard when driving. Have the issue inspected and fixed as soon as possible.