Fiat Kobelco EX355 Tier2, Техническое руководство

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EX355 T5-4-7
TROUBLESHOOTING B
E Mode Switch Travel Mode Switch MC Pump Control
Valve
• To select E mode.
ON: 0 V
→
E Mode
OFF: 5 V
→
Standard Mode
• To change travel speed at two
stages.
Fast Travel Mode: 0 V
Slow Travel Mode: 5 V
• To control engine, pump, and
valve operations.
• To develop pump control
pressure in response to the
oil flow rate passing through
the center bypass passage
in the control valve.
- • Discontinuity in Switch:
Travel speed is kept in slow
range (5 V).
• Problems may differ depending
on the trouble.
(Machine troubles shown below
signify that the logic circuit in
MC has some faults.)
• If the pump control valve
spool is seized, or the
spring is broken, pump con-
trol pressure does not
change.
• Broken Wire: Even if E
mode switch is depressed,
engine runs at full speed.
• Short Circuit: Engine speed
is not increased up to full
speed.
• Even if travel mode switch is
turned to the fast travel
mode position, travel speed
is un-changed.
• Even if key switch is turned to
the ON position, EC motor
does not rotate to the start
position so that engine cannot
start. Or, even if engine is
started, engine speed does not
increase.
• Pump swash angle is held to a
minimum, all function speeds
are slow.
• When the 5-spool side
pump control valve is faulty:
1.Left track travel speed only
is slow.
2.Swing function is also slow.
3.Arm speed is slow when
leveling.
4.Single operation of bucket,
boom, or arm is almost
normally performed.
• When 4-spool side pump
control valve is faulty:
1.Bucket single operation
speed is very slow.
2.Boom is not raised when
leveling.
3.Right track travel speed
only is slow.
4.Single operation of boom,
arm, or swing is almost
normally performed.
- -
Procedures may differ depending
on the locations of failures.
-
Monitor item:
E Mode Switch
Monitor item:
Selected Travel Mode Switch
- -
- - - -
- - - -
- -
• Before suspecting a failure in MC,
check the fuse in this control cir-
cuit.
-
T2-1 T2-1 - T3-3