79
Vehicle Dynamics and Driver Assist Systems
May 2017
Pressure Decrease Mode
During Pressure Decrease mode, the H/U motor pump is energized to produce additional
hydraulic pressure. However, the inlet valve is energized/closed preventing pressure from
increasing in the wheel cylinder/caliper. At the same time, the outlet valve is opened and brake
fluid is allowed to drain from the wheel cylinder/caliper decreasing pressure.
Energized
Pressure Decrease
Item Electrical State Mechanical State
Inlet Valve Closed
Outlet Valve Open
Motor Pump Energized
Energized
ON
M
DAMPER
CHAMBER
FROM MASTER CYLINDER
INLET
PORT
CLOSED
OUTLET
PORT
OPEN
WHEEL
CYLINDER
ELECTRIC
CURRENT IS ON
OUTLET SOL. VALVE
INLET SOL. VALVE
RESERVOIR
PUMP
MOTOR
CHECK
VALVE
ELECTRIC
CURRENT IS ON
Pressure Decrease Mode
Pressure Hold Mode
During Pressure Increase mode, the H/U motor pump is energized to produce additional
hydraulic pressure. Since the inlet valve is open and the outlet valve is closed, pressure is
increased in the wheel cylinder/caliper.
Not Energized
Pressure Hold
Item Electrical State Mechanical State
Inlet Valve Closed
Outlet Valve Closed
Motor Pump Energized
Energized
ON
M
DAMPER
CHAMBER
FROM MASTER CYLINDER
INLET
PORT
CLOSED
OUTLET
PORT
CLOSED
WHEEL
CYLINDER
OUTLET SOL. VALVE
INLET SOL. VALVE
RESERVOIR
PUMP
MOTOR
CHECK
VALVE
ELECTRIC
CURRENT IS ON
Pressure Hold Mode
3-59
3-60
To Next Page
Loading...
