Komatsu BR380JG-1E0, Shop Manual, Page: 776 / 841

40 Troubleshooting SEN02307-00
BR380JG-1E0
13
S-6 Engine lack output (or lacks power) 1
*1: Displayed failure codes [CA559] and [CA2249]
*2: Displayed failure codes [CA122] and [CA123]
General causes why engine lacks output
q
Insufficient intake of air
q
Insufficient supply of fuel
q
Defective spray condition of fuel
q
Improper selection of fuel
q
There is overheating
o
See “S-14 Coolant temperature becomes too
high (Overheating)”.
q
Controller is controlling in derate mode (limiting
injection rate (output) because of an error in
electrical system)
Causes
C
log
ged
a
ir
clean
er
e
leme
nt
Air
le
aka
ge fr
om
a
ir in
ta
ke pipin
g
S
eize
d t
ur
bo
cha
rg
er
, in
te
rf
er
en
ce o
f tu
rb
oc
ha
rg
er
D
ef
ective
con
ta
ct of valve an
d
va
lve seat
Im
pr
op
er
va
lve
cle
ar
an
ce
W
orn
p
isto
n ri
ng
, cylin
de
r
line
r
C
log
ged
a
ir
br
ea
the
r ho
le
of
fu
el t
an
k cap
Leakin
g,
clog
ge
d f
ue
l pip
ing
C
log
ged
fuel
filte
r
S
tu
ck, se
ized
sup
ply pum
p plun
ge
r
C
log
ged
in
je
cto
r,
de
fect
ive
spr
ay (
dir
t in
inject
or
)
Defective drive
of inject
or
(sig
na
l,
so
leno
id)
De
fe
ct
ive in
st
allat
io
n of
bo
ost
pr
essu
re
se
nso
r
(a
ir le
aka
ge)
D
ef
ective
bo
ost
pr
essur
e
se
nso
r, wir
ing
h
ar
ne
ss
C
log
ged
sp
ill
pip
in
g
Questions
Confirm recent repair history
Degree of use of machine Operated for long period
E E E E
Power was lost
Suddenly
Q w Q Q Q Q
Gradually
Q Q Q Q Q Q
Non-specified fuel is being used
Q Q Q
Replacement of filters has not been carried out according to Operation
and Maintenance Manual
w w
Engine oil must be added more frequently
Q Q
Dust indicator is red
w w
Air breather hole of fuel tank cap is clogged
w w
Fuel is leaking from fuel piping
w
Output becomes insufficient after short stop of operation
w
Check items
Color of exhaust gas
Black
w w
Blue under light load
w
When exhaust manifold is touched immediately after starting engine,
temperature of some cylinders is low
w w
When engine is cranked, interference sound is generated around
turbocharger
w
When engine is cranked, abnormal sound is generated around cylinder head
w
High idle speed is too high
Q
High idle speed under no load is normal, but speed suddenly drops when
load is applied
Q w Q Q
Engine does not pick up smoothly and combustion is irregular
w w Q Q w
There is hunting from engine (rotation is irregular)
Q Q Q Q Q
Blow-by gas is excessive
w w
T
rouble
shooting
Inspect air cleaner directly
q
Inspect air intake piping directly
q
When boost pressure is measured, it is found to be low
q q q
When compression pressure is measured, it is found to be low
q q
Inspect valve clearance directly
q
Inspect fuel piping
q
Inspect fuel filter, strainer directly
q
Inspect spill port check valve directly
q
Carry out troubleshooting according to “Rail Press (Very) Low Error (*1)”
indicated by code
q
When a cylinder is cut out for reduced cylinder mode operation, engine
speed does not change
q q
Inspect boost pressure sensor mount directly
q
Carry out troubleshooting according to “Chg Air Press Sensor High (Low)
Error (*2)” indicated by code
q
Remedy
Clea
n
Corr
ect
Replace Replace Ad
ju
st
Replace Clea
n
Corr
ect
Replace Replace Replace Replace Corr
ect
Replace Replace