ANTI-LOCK BRAKING SYSTEM — Solenoid Operation

BR-37spec table

Normal brake = inlet de-energized OPEN, outlet de-energized CLOSE — same hydraulic path as a non-ABS car when no slip is detected.

Solenoid Operation

Position	Inlet solenoid driver	Inlet hydraulic circuit	Outlet solenoid driver	Outlet hydraulic circuit
Pressure increase / Normal brake condition	OFF	OPEN	OFF	CLOSE
Pressure hold	ON	CLOSE	OFF	CLOSE
Pressure decrease	ON	CLOSE	ON	OPEN

Pressure increase / Normal brake condition

Inlet solenoid driverOFF

Inlet hydraulic circuitOPEN

Outlet solenoid driverOFF

Outlet hydraulic circuitCLOSE

Pressure hold

Inlet solenoid driverON

Inlet hydraulic circuitCLOSE

Outlet solenoid driverOFF

Outlet hydraulic circuitCLOSE

Pressure decrease

Inlet solenoid driverON

Inlet hydraulic circuitCLOSE

Outlet solenoid driverON

Outlet hydraulic circuitOPEN