Mazda RX-8 2009 Service Highlights page 151

During DSC control (to suppress understeer tendency) and TCS control
! When a large understeer tendency is determined, the traction switch and the stability control solenoid valves
are energized, switching the hydraulic circuits. At the same time, the pump motor is actuated to operate the
pump, thereby increasing pressure by supplying brake fluid pressure to the caliper piston of the inner rear
wheel or the slipping driving wheel. Also at this time, the inlet solenoid valve of the outer front wheel is
energized and the hydraulic circuit of this wheel is closed.
! After a pressure increase, brake fluid pressure is adjusted using the three pressure modes (reduction,
maintain, increase) so that the target wheel speed is obtained. (The following figure shows a left turn, or control
of left rear wheel spin (during pressure increase mode).)
Solenoid valve operation table
Traction control
solenoid valve
LF—RR RF—LR
During
pressure OFF ON
increase (open) (closed)
mode
During
pressure OFF ON
maintain (open) (closed)
mode
During
pressure OFF ON
reduction (open) (closed)
mode
Hydraulic circuit diagram
MASTER CYLINDER
TRACTION
CONTROL
SOLENOID
VALVE
STABILITY
CONTROL
SOLENOID
VALVE
INLET
SOLENOID
VALVE
OUTLET
SOLENOID
VALVE
DYNAMIC STABILITY CONTROL
Stability control
Inlet solenoid valve
solenoid valve
LF—RR RF—LR LF
OFF
OFF ON
(ope
(closed) (open)
n)
OFF
OFF (closed) (ope
n)
OFF
OFF (closed) (ope
n)
P
PUMP
RESERVOIR
OUTLET
RF LR
SOLENOID
VALVE
PRESSURE
INCREASE
Outlet solenoid valve
RF LR RR LF
ON OFF
OFF
(clos (clos (ope
(open)
ed) ed)
OFF ON OFF OFF
(clos (clos (ope (clos (ope
ed) ed) n) ed)
OFF ON OFF OFF
(clos (clos (ope (clos (ope
ed) ed) n) ed)
BRAKE FLUID
PRESSURE SENSOR
PUMP
MOTOR
RR
Pump
motor,
pump
RF LR RR
ON
OFF
Operating
(closed)
n)
ON
OFF
Operating
(closed)
n)
ON ON OFF
(ope (clos Operating
n) n) ed)
LF
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