Engine Does Not Start (Engine Does Not Turn) - Komatsu PC130-8 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. 3
Defective starting switch
3
(Internal disconnection)
Defective lock lever switch
4
(Internal disconnection)
Defective starting motor cut-
out relay R06 or R07 (Inter-
Possible causes
5
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)
PC130-8
Cause Standard value in normal state/Remarks on troubleshooting
a Prepare with starting switch OFF, then carry out troubleshoot-
ing without turning starting switch ON.
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
OFF and turn it to START and carry out troubleshooting in each
case.
Between (1) – (4)
a Prepare with starting switch OFF, then carry out troubleshoot-
ing without turning starting switch ON.
Between (1) – (3)
a Prepare with starting switch OFF, then carry out troubleshoot-
ing without turning starting switch ON.
a Prepare with starting switch OFF, then turn starting switch to
START and carry out troubleshooting.
Between B – E
Between C (R28) – 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
START and carry out troubleshooting.
Between B – chassis
chassis ground
If power supply and starting input are normal but starting motor
does not turn, starting motor is defective.
Min. 24 V
H15 (male) Starting switch
START
S14 (female) Lock lever
R06 (male), R07 (male)
Between (1) – (2)
Between (3) – (4)
Between (3) – (5)
Safety relay terminal
Power supply
Between R
Generation input
(R19-2) – E
Between S
Starting input
(R19-1) – E
Starting output
Starting motor terminals
Power supply
ground
Between C –
Starting input
SEN04123-01
Electrolyte specific gravity
(1 piece)
Min. 1.26
Resistance
OFF Min. 1 Mz
Max. 1 z
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
11