Proportional relay valve 480 202 ... 0 The proportional relay valve is used in the electronically controlled braking system to modulate the braking pressure on the front axle. It comprises the proportional solenoid valve, relay valve and pressure sensor. Electrical drive and monitoring takes place via the central module of the hybrid system (electro-pneumatically / pneumatically). The control current impressed by the electronic unit is transformed via the proportional solenoid valve into a control pressure for the relay valve. The proportional relay valve’s output pressure is proportional to this pressure.
The pneumatic drive on the relay valve takes place via the brake signal transmitter’s redundant (back- up) pressure. How it works: Description of components EBS 3. 11