Failure Code [7Rf4Kb] Short Circuit In Feeder Forward Epc Valve - Komatsu Galeo BR380JG-1E0 Shop Manual

40 Troubleshooting

Failure code [7RF4KB] Short circuit in feeder forward EPC valve

User code Failure code
— 7RF4KB
Contents of
• Ground short circuit is detected when EPC valve solenoid for feeder forward rotation is driven.
trouble
• Turns the output to the feeder forward EPC valve solenoid circuit OFF.
Action of
• Even if the cause of the failure disappears, the system does not reset itself until the starting switch is
controller
turned OFF.
Problem that
• The feeder does not rotate forward.
appears on
• When this trouble is detected, the horn sounds (3 times intermittently).
machine
• Since the controller detects short circuit while the solenoid output is turned ON, be sure to turn the
solenoid output ON when checking for reproduction of the failure after repair.
Related
• Feeder forward EPC valve solenoid drive current can be checked with the monitoring function
information
(Code: 24700, Feeder FWD EPC Curr.)
• The failure history is recorded.
Defective feeder for-
ward EPC valve sole-
1 noid
(Internal grounding
fault)
Possible
Short circuit with chas-
causes and
sis ground in wiring
standard value
2
harness (Contact with
in normal state
ground)
Defective work equip-
3 ment and pump con-
troller
Circuit diagram related to feeder forward EPC solenoid
BR380JG-1E0
Short circuit in feeder forward EPC valve
Trouble
(Work equipment and pump controller (work equipment control) system)
Cause
a Prepare with engine starting switch OFF, then carry out troubleshooting
without turning engine starting switch ON.
Between (2) and chassis ground
a Prepare with engine starting switch OFF, then carry out troubleshooting
without turning engine starting switch ON.
Between wiring harness between C03 (female)
(38) – A01 – V03 (female) (2) and chassis
ground
a Prepare with engine starting switch OFF, then carry out troubleshooting
without turning engine starting switch ON.
Between (38) and (13), (23)
Between (38) and chassis ground
Standard value in normal state/Remarks on troubleshooting
V03 (male)
Between (1) and (2)
C03 (female)
SEN02090-00
1
Resistance
7 – 14 z
Min. 1 Mz
Resistance Min. 1 Mz
Resistance
7 – 14 z
Min. 1 Mz
47