Hydraulic Oil Temperature Gauge Does Not Indicate Normally - Komatsu Galeo PC138US-8 Shop Manual

40 Troubleshooting
E-10 Hydraulic oil temperature gauge does not indicate normally
(1) While hydraulic oil temperature is rising normally, temperature gauge does not rise from white
Trouble range (C).
(2) While hydraulic oil temperature is stabilized normally, temperature gauge rises to red range (H).
• Signals of hydraulic oil temperature sensor are input to pump controller and then transmitted to
Related machine monitor through communication system.
information • Hydraulic oil temperature can be checked with monitoring function.
(Code: 04401 Hydraulic oil temperature)
Defective hydraulic oil tem-
1 perature sensor (Internal dis-
connection or short circuit)
Disconnection in wiring har-
ness (Disconnection in wiring
2
or defective contact in con-
nector)
Possible causes
Ground fault in wiring har-
and standard
3 ness (Short circuit with GND
value in normal
circuit)
state
Hot short (Short circuit with
4
24V circuit) in wiring harness
5 Defective pump controller
6 Defective machine monitor
Circuit diagram related
PC138US, USLC-8
Cause Standard value in normal state/Remarks on troubleshooting
a Prepare with starting switch OFF, then carry out troubleshoot-
Between (2) – chassis ground
a Prepare with starting switch OFF, then carry out troubleshoot-
Wiring harness between C01 (female) (29)
– P22 (female) (2)
Wiring harness between C01 (female) (46)
– P22 (female) (1)
a Prepare with starting switch OFF, then carry out troubleshoot-
Wiring harness between C01 (female) (29)
– P22 (female) (2)
a Prepare with starting switch OFF, then turn starting switch ON
Wiring harness between C01 (female) (29)
– P22 (female) (2)
a Prepare with starting switch OFF, then carry out troubleshoot-
Between (29) – chassis ground
If causes 1 – 5 are not detected, machine monitor may be defec-
tive. (Since trouble is in system, troubleshooting cannot be carried
out.)
ing without turning starting switch ON.
P22 (male)
Between (1) – (2)
ing without turning starting switch ON.
ing without turning starting switch ON.
and carry out troubleshooting.
ing without turning starting switch ON.
C01 (female)
Between (29) – (46)
SEN02467-00
1
Resistance
3.5 – 90 kz
Min. 1 Mz
Resis-
Max. 1 z
tance
Resis-
Max. 1 z
tance
Resis-
Min. 1 Mz
tance
Voltage Max. 1 V
Resistance
3.5 – 90 kz
Min. 1 Mz
23