Komatsu BR380JG-1E0, Shop Manual, Page: 678 / 841

SEN02094-00 40 Troubleshooting
26
BR380JG-1E0
Failure code [DHPBMA] Abnormality in R pump pressure sensor 1
User code Failure code
Trouble
Abnormality in R pump pressure sensor
(Work equipment and pump controller (pump control) system)
— DHPBMA
Contents of
trouble
• Signal voltage of R pump pressure sensor circuit is below 0.3 V or above 4.5 V.
Action of
controller
• Fixes R pump pressure at 0 MPa {0 kg/cm 2 } and continues control.
• If cause of failure disappears, system resets itself.
Problem that
appears on
machine
• Overheat prevention function does not work properly (machine will overheat more easily).
Related
information
a
If 5V circuit (3) and ground circuit (1) of pressure sensor are connected inversely, pressure sensor
will be broken. Accordingly, take extreme care when checking.
• R pump pressure can be checked with monitoring function. (Code: 01101 , R Pump Pressure)
• Method of reproducing failure code: Turn engine starting switch ON or start engine.
• The failure history is recorded.
Possible
causes and
standard value
in normal state
Cause Standard value in normal state/Remarks on troubleshooting
1
Defective 5V sensor
power supply 1 system If failure code [ DA25KP ] is also displayed, carry out troubleshooting for it
first.
2
Defective R pump
pressure sensor
(Internal defect)
a
Prepare with engine starting switch OFF, then turn engine starting
switch ON or start engine and carry out troubleshooting in each case.
S11 Voltage
Between (3) – (1) Power supply 4.5 – 5.5 V
Between (2) – (1) Signal 0.3 – 4.5 V
If voltage is abnormal, replace R pump pressure sensor with F pump pres-
sure sensor and check failure code. (If “E” of failure code goes off at this
time, R pump pressure sensor is defective.)
3
Disconnection in wiring
harness (Disconnec-
tion in wiring or defec-
tive contact in
connector)
a
Prepare with engine starting switch OFF, then carry out troubleshooting
without turning engine starting switch ON.
Wiring harness between C01 (female) (4), (10) –
J02 – S11 (female) (1)
Resistance Max. 1
z
Wiring harness between C01 (female) (2) – S11
(female) (2)
Resistance Max. 1
z
Wiring harness between C01 (female) (22) – J03
– S11 (female) (3)
Resistance Max. 1
z
4
Ground fault in wiring
harness (Short circuit
with GND circuit)
a
Prepare with engine starting switch OFF, then carry out troubleshooting
without turning engine starting switch ON.
Wiring harness between C01 (female) (2) – S11
(female) (2)
Resistance Min. 1 M
z
5
Hot short (Short circuit
with 24V circuit) in wir-
ing harness
a
Prepare with engine starting switch OFF, then turn engine starting
switch ON and carry out troubleshooting.
Wiring harness between C01 (female) (2) – S11
(female) (2)
Voltage Max. 1 V
6
Defective work equip-
ment and pump con-
troller
If causes 1 – 5 are not detected, pump controller may be defective.
(Since trouble is in system, troubleshooting cannot be carried out.)