Komatsu Galeo PC138US-8 Shop Manual page 592

40 Troubleshooting
Ground fault in wiring har-
2 ness (Short circuit with GND
circuit)
Possible causes
and standard
value in normal
state
Hot short (Short circuit with
3
24V circuit) in wiring harness
4 Defective pump controller
PC138US, USLC-8
Cause Standard value in normal state/Remarks on troubleshooting
Wiring harness between C01 (female) (16)
– P08 (female) (2), P08 (female) (1) – J03 –
ground (T08)
[Swing LEFT PPC pressure switch system]
Wiring harness between C01 (female) (9) –
J07 – P25 (female) (3)
[Pump pressure sensor system]
a Prepare with starting switch OFF, then turn starting switch ON
Wiring harness between C01 (female) (34)
– P01 (female) (2), P01 (female) (1) – J03 –
ground (T08)
[Bucket CURL PPC pressure sensor sys-
tem]
Wiring harness between C01 (female) (53)
– P03 (female) (2), P03 (female) (1) – J03 –
ground (T08)
[Swing LEFT PPC pressure sensor system]
Wiring harness between C01 (female) (73)
– P04 (female) (2), P04 (female) (1) – J03 –
ground (T08)
[Arm IN PPC pressure sensor system]
Wiring harness between C01 (female) (17)
– P05 (female) (2), P05 (female) (1) – J03 –
ground (T08)
[Bucket DUMP PPC pressure sensor sys-
tem]
Wiring harness between C01 (female) (16)
– P07 (female) (2), P07 (female) (1) – J03 –
ground (T08)
[Boom RAISE PPC pressure sensor sys-
tem]
Wiring harness between C01 (female) (16)
– P08 (female) (2), P08 (female) (1) – J03 –
ground (T08)
[Swing RIGHT PPC pressure sensor sys-
tem]
Wiring harness between C01 (female) (9) –
J07 – P25 (female) (3)
[Pump pressure sensor system]
If causes 1 – 3 are not detected, pump controller may be defective.
(Since trouble is in system, troubleshooting cannot be carried out.)
and carry out troubleshooting.
SEN02464-01
Resis-
Min. 1 Mz
tance
Resis-
Min. 1 Mz
tance
Voltage Max. 1 V
Voltage Max. 1 V
Voltage Max. 1 V
Voltage Max. 1 V
Voltage Max. 1 V
Voltage Max. 1 V
Voltage Max. 1 V
41