Engine Does Not Start - Komatsu ecot3 PC300LC-8 Shop Manual

40 Troubleshooting
E-1 Engine does not start
Trouble • Engine does not start (Engine does not turn).
• Engine starting circuit has following 2 start lock mechanisms:
Related infor- 1) Start lock by the machine monitor password
mation 2) Start lock by the lock lever
• In the case no error code for the engine controller mechanism is indicated.
1 Low charge level of battery
Defective fuse No. 3, No. 17
2
or fusible link F04 and F05
Defective starting switch
3
(Internal disconnection)
Defective safety lock switch
4
(internal short circuit)
Possible causes
and standard
value in normal
Defective starting motor cut-
state
out relay R06 or R07 (Inter-
5
nal short circuit or ground
fault)
Defective starting motor
6 (Internal disconnection or
breakage)
Defective alternator
7
(Internal short circuit)
PC300, 350-8
Cause Standard value in normal state/Remarks on troubleshooting
If fuse or fusible link is burnt out, the circuit probably has ground
fault.
In the case the machine monitor does not light up, check the power
circuit between the battery and the fuse.
a
Between (1) – (4)
a
Between (1) – (3)
a
a
Power supply: Between terminal
B and chassis ground
Starting input: Terminal C – chas-
sis ground
a
Terminal R – chassis ground
Battery voltage
Min. 24 V
Prepare with starting switch OFF, then carry out troubleshoot-
ing without turning starting switch ON.
H15 (male) Position
Prepare with starting switch OFF, then carry out troubleshoot-
ing without turning starting switch ON.
S14 (female) Lock lever
Prepare with starting switch OFF, then carry out troubleshoot-
ing without turning starting switch ON.
R06 (male), R07 (male)
Between (1) – (2)
Between (3) – (4)
Between (3) – (6)
Prepare with starting switch OFF, then start engine and carry
out troubleshooting.
(If power supply and starting input and output are normal but
starting motor does not turn, starting motor is defective.)
Starting motor
Prepare with starting switch OFF, then turn starting switch ON
or start engine and carry out troubleshooting.
Alternator
SEN02632-02
Specific gravity of battery
Min. 1.26
Resistance
OFF Min. 1 Mz
Max. 1 z
START
Resistance
Free Min. 1 Mz
Max. 1 z
Lock
Resistance
100 – 500 z
Min. 1 Mz
Max. 1 z
Starting
Voltage
switch
20 – 30 V
When
started
20 – 30 V
Voltage
Max. 1 V
1
7