Abs Modulator - Honda EP3 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. lt is a circulating-type modulator
b e c a u s e t h e b r a k e f l u i d c i r c u l a t e s t h r o u g h t h e c a l i p e r , r e s e r v o i r , a n d t h e m a s t e r c y l i n d e r . T h e h y d r a u l i c c o n t r o l
h a s
three modes: pressure intensifying, pressure retaining, and pressure reducing. The hydraulic circuit is an independent
f o u r - c h a n n e l t y p e , o n e c h a n n e l f o r e a c h w h e e l .
Pressure intensifying mode: Inletvalve open, outlel valve closed
M a s t e r c y l i n d e r f l u i d i s p u m p e d o u t t o t h e c a l i p e r .
Pressure retaining mode: lnlet 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
Caliper fluid flows through the outlet valve to the reservoir.
lvlotor operation mode:
When starting the pressure reducing mode, the pump motor is ON.
When stopping ABS operation, the pump motor is OFF.
T h e c a l i p e r f l u i d i s p u m p e d o u t b y t h e p u m p , t h r o u g h t h e d a m p i n g c h a m b e r , t o t h e
m a s t e r c v l i n d e r .
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