Komatsu PC130-7, Shop Manual

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PC130-7
20-311
TROUBLESHOOTING
Error code [108] (Overheating of engine coolant)
Circuit diagram related to engine coolant temperature sensor
User code Error code
Trouble Overheating of engine coolant (Monitor panel system)
– 108
Contents of
trouble
• The signal circuit of the engine coolant temperature sensor inputs 99 o or higher temperature while the
engine is running.
Action of
monitor panel
• None in particular.
Problem that
appears on
machine
• If the machine is operated as it is, the engine may be seized.
Related
information
• If the engine coolant temperature monitor of the monitor panel flashes while the engine is running, this
error code is recorded.
• The input state (ON/OFF) from the engine coolant temperature sensor can be checked with the moni-
toring function. (Code: 041, by 10 mV)
Possible causes
and standard
value in normal
state
Cause Standard value in normal state/Remarks on troubleshooting
1
Overheating of engine
(When system is normal) The engine may have overheated. Find the cause and check the
engine for damage, and then repair.
2
Defective engine coolant
temperature sensor (Inter-
nal short circuit)
a
Prepare with starting switch OFF, then carry out troubleshooting with-
out turning starting switch.
E05 (male)
Engine coolant
temperature
Resistance
Between (1) and (2)
10 – 100 °C
3.5k – 90 k
z
Between (2) and
chassis ground
Min. 1 M
z
3
Short circuit with chassis
ground in wiring harness
(Contact with ground cir-
cuit)
a
Prepare with starting switch OFF, then carry out troubleshooting with-
out turning starting switch.
Between P02 (female) (1) – E05 (female) (2)
wiring harness and chassis ground
Resistance Min. 1 M
z
4 Defective monitor panel
a
Prepare with starting switch OFF, then carry out troubleshooting with-
out turning starting switch.
P02
Engine coolant
temperature
Resistance
Between (1) and (13)
10 – 100 °C
3.5k – 90 k
z
Between (1) and
chassis ground
Min. 1 M
z
[108]
(1)