Komatsu 80001 User Manual

SEN04121-02 40 Troubleshooting
20 PC130-8
Failure code [DHSHMA] Travel left reverse PPC press sensor
abnormality 1
User code Failure code
Trouble
Travel left reverse PPC pressure sensor abnormality
(Pump controller system)
E20 DHSHMA
Contents of
troubl
e
• Signal voltage of travel left reverse PPC pressure sensor circuit is below 0.3 V or above 4.5 V.
Action of
control
ler
• Fixes travel left reverse PPC pressure at 0 MPa {0 kg/cm
2
} and continues control.
• If cause of failure disappears, system resets itself.
Problem that
a
ppears on
machine
• Automatic decelerator ca
nnot be reset.
• Travel left reverse performance lowers.
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.
• Travel left reverse PPC pressure can be checked with monitoring function. 
(Code: 07
104 Travel left reverse PPC pressure)
• Method of reproducing failure code: Turn starting switch ON or start engine.
Possible causes
and standard
value in normal
state
Cause Standard value in normal state/Remarks on troubleshooting
1
Defective 5V sensor power
suppl
y 1 system
If failure code [DA25KP] is also displayed, carry out troubleshoot-
ing for it first.
2
Defective travel left reverse
PPC pressure sensor (Inter-
nal defect)
a Prep
are with starting switch OFF, then turn starting switch ON
or start engine and carry out troubleshooting in each case.
P12 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 travel left reverse PPC pressure
sensor with ano
ther PPC pressure sensor and check failure code.
(If "E" of failure code goes off at this time, travel left reverse PPC
pressure sensor is defective.)
3
Disconnection in wiring har-
ness (Disconnection in wiring
or
defective contact in con-
nector)
a Prep
are with starting switch OFF, then carry out troubleshoot-
ing without turning starting switch ON.
Wiring harness between CP01 (female) (18)
– P12 (fe
male) (1)
Resis-
tance
Max. 1 z
Wiring harness between CP01 (female) (13)
– P12 (fe
male) (2)
Resis-
tance
Max. 1 z
Wiring harness between CP01 (female) (9)
– P12 (fe
male) (3)
Resis-
tance
Max. 1 z
4
Ground fault in wiring har-
ness (Short circuit with GND
circuit)
a Prep
are with starting switch OFF, then carry out troubleshoot-
ing without turning starting switch ON.
Wiring harness between CP01 (female) (13)
– P12 (fe
male) (2) and chassis ground
Resis-
tance
Min. 1 Mz
5
Hot short (Short circuit with
24V circuit)
in wiring harness
a Prep
are with starting switch OFF, then turn starting switch ON
and carry out troubleshooting.
Wiring harness between CP01 (female) (13)
– P12 (fe
male) (2) and chassis ground
Voltage Max. 1 V
6 Defective pump controller
If causes 1 – 5 are not detected, pu
mp controller may be defective.
(Since trouble is in system, troubleshooting cannot be carried out.)

Komatsu 80001 Specifications

General

Brand	Komatsu
Model	80001
Category	Excavators
Language	English