Nissan Sentra. Manual - part 157
SYSTEM
BRC-15
< SYSTEM DESCRIPTION >
[VDC/TCS/ABS]
C
D
E
G
H
I
J
K
L
M
A
B
BRC
N
O
P
Front RH brake caliper
• Since the suction valve 1 and the ABS OUT valve are closed and the cut valve 1 and the ABS IN valve are
open, the fluid pressure applied on the front RH brake caliper is reduced by supplying the fluid pressure to
the master cylinder via the ABS IN valve and the cut valve 1. The pressurization for the right caliper is con-
trolled separately from the left caliper.
Front LH brake caliper
• Since the suction valve 2 and the ABS OUT valve are closed and the cut valve 2 and the ABS IN valve are
open, the fluid pressure applied on the front LH brake caliper is reduced by supplying the fluid pressure to
the master cylinder via the ABS IN valve and the cut valve 2. The pressurization for the left caliper is con-
trolled separately from the right caliper.
Rear RH brake caliper/wheel cylinder
• Since the suction valve 2 and the ABS OUT valve are closed and the cut valve 2 and the ABS IN valve are
open, the fluid pressure applied on the rear RH brake caliper/wheel cylinder is reduced by supplying the fluid
pressure to the master cylinder via the ABS IN valve and the cut valve 2. The pressurization for the right cal-
iper/wheel cylinder is controlled separately from the left caliper/wheel cylinder.
Rear LH brake caliper/wheel cylinder
• Since the suction valve 1 and the ABS OUT valve are closed and the cut valve 1 and the ABS IN valve are
open, the fluid pressure applied on the rear LH brake caliper/wheel cylinder is reduced by supplying the fluid
pressure to the master cylinder via the ABS IN valve and the cut valve 1. The pressurization for the left cali-
per/wheel cylinder is controlled separately from the right caliper/wheel cylinder.
Component Parts and Function
VALVE OPERATION (ABS AND EBD FUNCTIONS)
The control unit built into the ABS actuator and electric unit (control unit) controls fluid pressure of the brake
calipers by operating each valve.
Name
Not activated
During pressure decreases
Cut valve 1
Power supply is not supplied (open)
Power supply is not supplied (open)
Cut valve 2
Power supply is not supplied (open)
Power supply is not supplied (open)
Suction valve 1
Power supply is not supplied (close)
Power supply is not supplied (close)
Suction valve 2
Power supply is not supplied (close)
Power supply is not supplied (close)
ABS IN valve
Power supply is not supplied (open)
Power supply is not supplied (open)
ABS OUT valve
Power supply is not supplied (close)
Power supply is not supplied (close)
Each brake caliper and each wheel cylinder
(fluid pressure)
—
Pressure decreases
Component
Function
Pump
Returns the brake fluid reserved in reservoir to master cylinder by reducing pressure.
Motor
Activates the pump according to signals from ABS actuator and electric unit (control unit).
Cut valve 1
Cut valve 2
Shuts off the ordinary brake line from master cylinder.
Suction valve 1
Suction valve 2
Supplies the brake fluid from master cylinder to the pump.
ABS IN valve
Switches the fluid pressure line to increase or hold according to signals from control unit.
ABS OUT valve
Switches the fluid pressure line to increase, hold or decrease according to signals from control unit.
Return check valve
Returns the brake fluid from brake caliper and wheel cylinder to master cylinder by bypassing orifice
of each valve when brake is released.
Reservoir
Temporarily reserves the brake fluid drained from brake caliper, so that pressure efficiently decreas-
es when decreasing pressure of brake caliper and wheel cylinder.
Pressure sensor
Detects the brake fluid pressure and transmits signal to ABS actuator and electric unit (control unit).