CL TYPE S V6-3.2L SOHC (2001)
Hydraulic Control Assembly - Antilock Brakes: Description and Operation
ABS/TCS
Modulator Unit
The modulator unit consists of the inlet solenoid valve, outlet solenoid valve, TCS Normally Open (NO) solenoid valve, TCS Normally Closed (NC)
solenoid valve, reservoir, pump, pump motor, and the damping chamber. The modulator controls the caliper fluid pressure directly. It is a
circulating-type modulator because the brake fluid circulates through the caliper, the reservoir, and the master cylinder. The hydraulic control has
three modes: pressure intensifying, pressure retaining, and pressure reducing. The hydraulic circuit is an independent four channel type, one channel
for each wheel.
ABS Control
Pressure intensifying mode
TCS NO valve open, TCS NC valve closed, inlet valve open, outlet valve closed.
Master cylinder fluid is pumped out to the caliper.
Pump Motor
When starting the pressure reducing mode, the pump motor is ON. When stopping ABS operation, the pump motor is OFF.
The reservoir fluid is pumped out by the pump, though the damping chamber. to the master cylinder.
Pressure retaining mode
TCS NO valve open, TCS NC valve closed, inlet valve closed, outlet valve closed.
Caliper fluid is retained by the inlet valve and outlet valve.
Pressure reducing mode
