It informs the engine control unit if there is sufficient pressure in the brake booster for correct operation of the booster. When the depression is not level, the control unit modifies the position of the throttle, closing it to increase the vacuum generated by the engine itself and the depression in the brake booster within the permitted parameters.
LOCATION
It is located either connected to the brake booster or integrated within the vacuum check valve of a traditional brake booster.
COMMON FAULT SYMPTOMS
- Dirt
- Blockage in the brake booster filter
FAULT EFFECTS
- The brake pedal feels firm
- The brake pedal does not respond