Valve Operation for ENGINE OFF

TM 9-2320-312-24-2

Systems Operation Section

The magnetic force that is holding poppet (9)

closed is opposed by reduced hydraulic pressure

inside the spool chamber. The reduced hydraulic

pressure inside the spool chamber is trying to

open poppet (9). This reduced hydraulic pressure

increases until the reduced hydraulic pressure

overcomes the mechanical force of solenoid (11).

When the reduced hydraulic pressure overcomes

the mechanical force of solenoid (11), poppet (9)

opens. The open poppet allows a flow path to

drain for some of the reduced pressure oil (8).

Discharging part of reduced pressure oil (8) to drain

lowers the hydraulic pressure. When the hydraulic

pressure of reduced pressure oil (8) decreases

below the magnetic force on poppet (9), the poppet

closes again.

Valve Operation for ENGINE OFF

g00295336

Illustration 12

Operation of the injection actuation pressure control valve (engine off)

(1) Pump outlet pressure (none)

(3) Closed drain port

(2) Current from ECM (none)

(4) Poppet (open position)