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HOMESERVICE MANUALSCHEVROLET2006COBALT SS, 4D SEDAN, STANDARDREPAIR AND DIAGNOSISEXTERNAL PAGESDIFFERENT CARSECTION 761 (ABS COMPONENTS)SYSTEM DESCRIPTIONMODULATOR UNIT
2006 Chevrolet Cobalt SS, 4D Sedan, Standard

Modulator Unit

2006 Chevrolet Cobalt SS, 4D Sedan, StandardSECTION Modulator Unit
WARNING: This page is about a different car, the 2011 Honda Insight and 2010 Honda Insight. However, it is still accessible from the selected car via links, so may be relevant.

The modulator unit consists of the inlet solenoid valve, the outlet solenoid valve, the CAS NO (normally open) solenoid valve, the CAS NC (normally closed) solenoid valve, the reservoir, the pump, and the pump motor.

The hydraulic control has three modes of ABS action; pressure intensifying, pressure retaining, and pressure reducing. The pressure adding mode is combined at brake assist action with the CAS NO solenoid valve and CAS NC solenoid valve.

The hydraulic circuit is an independent four channel type; one channel for each wheel.

Fig 1: Modulator Unit Circuit Diagram
G06430784Courtesy of AMERICAN HONDA MOTOR CO., INC.

IN INLET SOLENOID VALVE (NORMALLY OPEN) OUT. OUTLET SOLENOID VALVE (NORMALLY CLOSED) 

SOLENOID VALVE REFERENCE

Mode CAS NO Valve CASNC Valve Inlet Solenoid Valve Outlet Solenoid Valve Brake Fluid
Pressure intensifying mode  open closed open closed Master cylinder fluid is pumped out to the caliper.
Pressure retaining mode  open closed closed closed Caliper fluid is retained by the inlet and outlet valves.
Pressure reducing mode  open closed closed open
  • Caliper fluid flows through the outlet valve to the reservoir.
  • The motor pumps the reservoir fluid through the damping chamber to the master cylinder(1).
Pressure adding mode  open closed closed open
  • Master cylinder fluid is pumped out by the pump through the CAS NC valve to the caliper.
  • Caliper fluid pressure exceeds master cylinder pressure.
(1) The motor will continue running until the operation of the one anti-lock brake control is finished with the first pressure reducing mode.
RENDER: 1.0x

NO RELATED

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