Abs Modulator - Honda Civic 2002-2003 Service Manual

ABS Components
System Description (cont'd)
ABS Modulator
The ABS modulator consists of the inlet solenoid valves, outlet solenoid valves, reservoir, pump, pump motor, and the
damping chamber. The modulator reduces the caliper fluid pressure directly. It is a circulating-type modulator
because the brake fluid circulates through the caliper, 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.
ASS MODULA TOA·CONTROL UNIT
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A8S CONTROL UNIT
MASTER CYLINDER
MODULATOR UNIT Me2 Mel
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DAMPING CHAMBER DAMPING CHAMBER
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MOTOR
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IN.
INLET VALVE (NORMAllY OPENI
OUT:
OUTLET VALVE [NORMALLY CLOSEDI
Pressure intensifying mode: Inlet valve open, outlet valve closed
Master cylinder fluid is pumped out to the caliper.
Pressure retaining mode: Inlet valve closed, outlet valve closed
Caliper fluid is retained by the inlet valve and outlet valve.
Pressure reducing mode: Inlet valve closed, outlet valve open
Motor operation mode:
19-40
Caliper fluid flows through the outlet valve to the reservoir.
When starting the pressure reducing mode, the pump motor is ON.
When stopping ASS operation, the pump motor is OFF.
The caliper fluid is pumped out by the pump, through the damping chamber, to the
master cylinder.
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