ESP valve block: Notes

Fig 1: Identifying ESP Valve Block (1 Of 2)

Courtesy of SAAB-SCANIA OF AMERICA, INC.

Fig 2: Identifying ESP Valve Block (2 Of 2)

Courtesy of SAAB-SCANIA OF AMERICA, INC.

The ESP valve block consists of 12 electromagnetic valves that control the brake pressure to the brakes during ABS, TCS and ESP braking.

The pressure-increase and pressure-reducing valves are the same as in the TC/ABS unit to their design and operation. In order to enable ESP regulation, the valves are connected to the rear wheel brakes and the inlet and outlet valves are also activated during ESP regulation. This arrangement is to enable the brake pressure on all four wheels to be modulated. This solution makes it possible to build up pressure, maintain pressure and reduce pressure individually on all four wheels.

If the driver applies the brakes while ESP regulation is active, the brake pressure sensor will inform the control module of the input brake pressure in the hydraulic unit. With this information, the brake pressure to the wheels not under ESP regulation can be controlled to correspond to the driver's braking force. The wheel under ESP regulation when the brakes are applied is controlled according to the ESP criteria.

See the description and illustrations under as "ESP REGULATION AND BRAKE APPLICATION ".

The pump is active continuously during ESP regulation.