Komatsu 75001, Shop Manual

Page: 992 / 1293

SEN03850-00
WA250, 250PZ-6 40-600
11
600 Troubleshooting of engine (S-mode)
S-4 Engine stops during operations
S-4 Engine stops during operations
1
*1: Failure codes [CA559] and [CA2249] in the display of code
General causes why engine stops during operations
q
Internal parts of engine seized
q
Insufficient supply of fuel
q
There is overheating
q
Problem in hydraulic pump
Causes
B
rok
en d
y
n
a
mi
c va
lv
e sy
st
em (
v
a
lv
e
, r
o
ck
er
ar
m
, e
tc
.)
B
rok
en,
se
iz
ed
p
ist
on
, co
nn
ec
ti
ng
r
o
d
B
rok
en,
se
iz
ed
c
ran
ksh
af
t be
ar
in
g
B
rok
en,
se
iz
ed
g
e
a
r t
ra
in
In
su
ffic
ie
n
t fu
e
l in
ta
n
k
C
log
ged
ai
r
b
rea
ther
h
o
le
of
f
u
e
l t
a
nk ca
p
L
eak
in
g,
cl
og
ge
d f
ue
l pi
pi
n
g
C
log
gi
ng
o
f f
u
e
l f
ilt
er
,
st
ra
in
e
r
C
log
gi
ng
f
e
ed p
u
mp
ga
uze
f
ilt
e
r
B
rok
en,
se
iz
ed
f
e
ed
p
u
m
p
B
rok
en s
u
p
p
ly
pu
mp sh
af
t
S
tuc
k
, s
e
iz
e
d
su
pp
ly
p
u
m
p
pl
un
ge
r
B
rok
en a
u
xi
lia
ry eq
ui
pm
en
t (
p
u
m
p
, co
mp
re
ss
or
,
e
tc.
)
D
e
fe
ct
iv
e hy
dr
a
u
lic
p
u
m
p
D
e
fe
ct
iv
e en
gi
ne
con
tr
o
lle
r
p
o
w
e
r
su
p
p
ly
w
ir
ing
D
e
fe
c
ti
ve
s
ta
rti
n
g
s
w
itc
h
w
ir
in
g
Q
u
es
ti
on
s
Confirm recent repair history
Degree of use of machine Operated for long period E E
Condition when engine
stopped
Abnormal noise was heard and engine
stopped suddenly
w w w w Q w Q w w
Engine overheated and stopped w Q Q Q Q
Engine stopped slowly w Q Q Q Q
There was hunting and engine stopped w Q Q Q Q
Non-specified fuel is being used Q Q Q Q
Replacement of filters has not been carried out according to Operation
and Maintenance Manual
w w
Fuel level monitor indicates low level w
When fuel tank is inspected, it is found to be empty w
Air breather hole of fuel tank cap is clogged w
Fuel is leaking from fuel piping w
C
h
e
ck i
te
ms
Rust and water are found when fuel tank is drained w w
Metal particles are found when oil pan is drained w w Q Q
When engine is cranked by
hand
Does not turn at all w w
Turns in opposite direction w
Moves by amount of gear backlash w w
Supply pump shaft does not turn w
Engine turns, but stops when load is applied to machine w
T
ro
ubl
e
s
ho
ot
ing
Inspect dynamic valve system directly q
C
a
rr
y
ou
t t
rou
bl
es
ho
ot
in
g i
n
H
-mo
d
e
Inspect piston, connecting rod directly q
Inspect crankshaft bearing directly q
Inspect gear train directly q
Inspect fuel filter, strainer directly q
Inspect feed pump gauze filter directly q
Inspect feed pump directly q
Carry out troubleshooting according to “No-pressure feed by supply
pump (*1)” in display of code
q q
Engine rotates when pump auxiliary equipment (pump, compressor, etc.)
is removed
q
Check controller power supply wiring q
Check starting switch wiring q
Remedy
R
e
pl
ac
e
R
e
pl
ac
e
R
e
pl
ac
e
R
e
pl
ac
e
Ad
d
Cl
e
a
n
Co
rr
e
c
t
Cl
e
a
n
Cl
e
a
n
R
e
pl
ac
e
R
e
pl
ac
e
R
e
pl
ac
e
R
e
pl
ac
e
—
Co
rr
e
c
t
Co
rr
e
c
t