Komatsu PC130-7, Shop Manual

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20-340
PC130-7
TROUBLESHOOTING
Error code [224] (Abnormality in pump pressure sensor)
User code Error code
Trouble
Abnormality in pump pressure sensor
(Governor and pump controller system)
– 224
Contents of
trouble
• The signal voltage from the pump pressure sensor is below 0.3 V or above 4.72 V.
Action of
controller
• Sets the pump pressure to 0 MPa {0 kg/cm
2
} for control.
• If the cause of the failure disappears, the system resets itself.
Problem that
appears on
machine
• The travel speed does not change automatically (The travel load pressure cannot be sensed).
• Cut-off function dose not work (The work equipment pressure can not be detected.)
Related
information
• If the 5-V circuit (B) and ground circuit (A) of the pressure sensor are connected inversely, the pressure
sensor will be broken. Accordingly, take extreme care when checking.
• The input state (ON/OFF) from the pump pressure sensor can be checked with the monitoring function.
(Code: 011, 012, by 1 kg/cm
2
)
Possible causes
and standard
value in normal
state
Cause Standard value in normal state/Remarks on troubleshooting
1
Defective sensor power
supply
If error code [226] is displayed, carry out troubleshooting for it first.
2
Defective pump pressure
sensor (Internal defect)
a
Prepare with starting switch OFF, then hold starting switch ON or start
engine and carry out troubleshooting.
A51 Voltage
Between (B) and (A) Power supply 4.5 – 5.5 V
Between (C) and (A) Signal 0.5 – 4.5 V
The pressure sensor voltage is measured with the wiring harness con-
nected. Accordingly, if the voltage is abnormal, check the wiring har-
ness and controller, too, for another cause of the trouble, and then
judge.
3
Disconnection in wiring
harness (Disconnection in
wiring harness or defective
contact in connector)
a
Prepare with starting switch OFF, then carry out troubleshooting with-
out turning starting switch.
Wiring harness between C01 (female) (22) and
J07 and A51 (female) (B)
Resistance
Max. 1
z
Wiring harness between C01 (female) (10) and
A51 (female) (A)
Resistance
Max. 1
z
Wiring harness between C01 (female) (8) and
A51 (female) (C)
Resistance Max. 1
z
4
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 C01 (female) (8) – A51 (female) (C)
wiring harness and chassis ground
Resistance
Min. 1 M
z
5
Short circuit with power
source in wiring harness
(Contact with 24-V circuit)
a
Prepare with starting switch OFF, then turn starting switch ON and car-
ry out troubleshooting.
Between C01 (female) (22) – J07 – A51
(female) (B) wiring harness and chassis ground
Voltage Max. 1 V
Between C01 (female) (8) – A51 (female) (C)
wiring harness and chassis ground
Voltage Max. 1 V
6
Defective governor and
pump controller
a
Prepare with starting switch OFF, then turn starting switch ON and car-
ry out troubleshooting.
C01 Voltage
Between (22) and (10) Power supply 4.5 – 5.5 V
Between (8) and (10) Signal 0.5 – 4.5 V
[224]
(1)