jcb JS300 Service Manual page 502

Engine Idle Control
When the operator selects this function the MECU
switches off the output to the pump proportional solenoid
valve (set to 0 mA) and requests the engine idle rpm
setting from the engine ECU by means of a CAN message.
When the engine is in idle mode the power band bar graph
on the LCD monitor is shown in grey.
The engine can be set to a no load idle position in one of
two ways:
1 By use of the auto idle button 1.
Fig 13.
Pressing the auto idle button activates the auto idle
function. Pressing the button again de-activates the
auto idle function. When auto idle is active an icon
displays on the LCD monitor.
When auto idle is active the engine rpm will
automatically be set to idle if the machine is not
working for a pre-set period of time. The time period
can be set by the operator.
To prevent the auto idle function setting the engine
speed to idle when the machine is working or resume
working from idle, the MECU monitors several inputs.
The MECU will not set the engine speed to idle if one
or more of the following inputs are active:
– The pilot pressure switch input.
– The travel pilot pressure switch input.
– The auxiliary hydraulic controls (detected by the
HECU and sent to the MECU by means of a CAN
message) (if fitted).
– The hammer hydraulic control (detected by the HECU
and sent to the MECU by means of a CAN message)
(if fitted).
– Overload caution pressure switch (if fitted).
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1
Engine Throttle and Power Mode Control
2 By use of the one touch idle control button 1. The
button is located in the RH joystick control lever 2.
Pressing the one touch idle button sets the engine
speed to idle. Pressing the button again returns
control of the engine speed to the hand throttle
control.
If the one touch idle button is set to engine idle when
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the engine is not running the engine will remain at idle
after start up.
The automatic warm up function operates normally. If
the one touch idle button is set to engine idle during
the warm up sequence automatic warm up is
cancelled and the engine speed is set to idle.
The engine idle is also controlled by the automatic warm
up and cold idle functions. Refer to the applicable topic.
K Engine Exhaust After Treatment ( T C-88)
9813/5100-1
Section C - Electrics
Engine and Power Control
1
Fig 14.
2
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