Engine Does Not Start (Engine Does Not Turn) - Komatsu Galeo PC138US-8 Shop Manual

40 Troubleshooting
E-3 Engine does not start (Engine does not turn)
Trouble

• Engine does not start (Engine does not turn).

• Engine starting circuit has following 2 start lock mechanisms.
Related
1) Start lock with password of machine monitor
information
2) Start lock with lock lever
1 Low charge level of battery
2 Defective fuse No. 20
Defective starting switch
3
(Internal disconnection)
Defective lock lever switch
4
(Internal disconnection)
Defective starting motor cut-
out relay R06 or R07 (Inter-
5
Possible causes
nal disconnection or short
and standard
circuit)
value in normal
state
Defective starting motor
6
safety relay (Internal defect)
Defective starting motor
7
(Internal defect)
PC138US, USLC-8
Cause Standard value in normal state/Remarks on troubleshooting
a Prepare with starting switch OFF, then carry out troubleshoot-
Battery voltage (2 pieces)
If fuse is broken, circuit probably has ground fault. (See cause 10.)
a Prepare with starting switch OFF, then keep starting switch
Between (1) – (4)
a Prepare with starting switch OFF, then carry out troubleshoot-
Between (1) – (3)
a Prepare with starting switch OFF, then carry out troubleshoot-
a Prepare with starting switch OFF (with only terminal C discon-
Between B – E
Between C (R18) – E
If power supply, generation input, and starting input are normal but
starting output is not normal, starting motor safety relay is defec-
tive.
a Prepare with starting switch OFF, then turn starting switch to
Between B – chassis
Between C (E10) –
chassis ground
If power supply and starting input are normal but starting motor
does not turn, starting motor is defective.
ing without turning starting switch ON.
Min. 24 V
OFF and turn it to START and carry out troubleshooting in each
case.
H15 (male) Starting switch
ing without turning starting switch ON.
S14 (female) Lock lever
ing without turning starting switch ON.
R06 (male), R07 (male)
Between (1) – (2)
Between (3) – (4)
Between (3) – (5)
nected), then turn starting switch to START and carry out trou-
bleshooting.
Safety relay terminal
Power supply
Between R
Generation input
(R17-2) – E
Between S
Starting input
(R17-1) – E
Starting output
START and carry out troubleshooting.
Starting motor terminals
Power supply
ground
Starting input
SEN02467-00
Electrolyte specific gravity
(1 piece)
Min. 1.26
Resistance
OFF Min. 1 Mz
Max. 1 z
START
Resistance
Free Min. 1 Mz
Max. 1 z
Lock
Resistance
300 – 600 z
Max. 1 z
Min. 1 Mz
Voltage
20 – 30 V
Max. 1 V
20 – 30 V
20 – 30 V
Voltage
20 – 30 V
20 – 30 V
1
9