jcb JS300 Service Manual page 524

Load Assist Valve
K Load assist valve - hydraulic schematic ( T C-100)
K Load assist valve - electrical schematic ( T C-101)
The load assist solenoid valve 2 is located next to the 8
station solenoid valve block 1.
The solenoid 3 is connected to the MECU via harness
connector C351. The MECU energises and de-engergises
the solenoid in response to a CANbus message from the
engine ECU. The solenoid will automatically energise
during manual or forced regeneration of the DPD particle
filter.
The valve is connected in the hydraulic negative control
line from the main control valve to pump 2. During normal
operation the solenoid is de-energised and it allows free
flow of the control signal to pass to pump 2 from Ps2 on the
main control valve. The pump regulation system operates
normally.
When the solenoid 9 energises, oil at servo pressure flows
to the poppet valve 15A via the 8 station valve block 60.
The poppet valve spool moves and blocks the negative
C-99
1
C351
Fig 39.
control line connected to port Pi2 at pump 2. The pump
control pressure decays and brings the pump onto full flow.
With the pump on full flow the engine load increases, this
has the effect of raising the exhaust gas temperature to
enable effective regeneration of the particle filter in the
DPD.
9813/5100-1
Section C - Electrics
Engine and Power Control
Engine Exhaust After Treatment
3
2
C146740
C-99