Komatsu 80001 User Manual

40 Troubleshooting SEN04123-01
PC130-8
11
E-3 Engine does not start (Engine does not turn) 1
Trouble • Engine does not start (Engine does not turn).
Related
information
• Engine starting circuit has following 2 start lock mechanisms.
1) Start lock with password of machine monitor
2) Start lock with lock lever
Possible causes
and standard
value in normal
state
Cause Standard value in normal state/Remarks on troubleshooting
1 Low charge level of battery
a Prepare with starting switch OFF, then carry out troubleshoot-
ing without turning starting switch ON.
Battery voltage (2 pieces)
Electrolyte specific gravity
(1 piece)
Min. 24 V Min. 1.26
2 Defective fuse No. 3 If fuse is broken, circuit probably has ground fault. (See cause 10.)
3
Defective starting switch
(Internal disconnection)
a Prepare with starting switch OFF, then keep starting switch
OFF and turn it to START and carry out troubleshooting in each
case.
H15 (male) Starting switch Resistance
Between (1) – (4)
OFF Min. 1 Mz
START Max. 1 z
4
Defective lock lever switch
(Internal disconnection)
a Prepare with starting switch OFF, then carry out troubleshoot-
ing without turning starting switch ON.
S14 (female) Lock lever Resistance
Between (1) – (3)
Free Min. 1 Mz
Lock Max. 1 z
5
Defective starting motor cut-
out relay R06 or R07 (Inter-
nal disconnection or short
circuit)
a Prepare with starting switch OFF, then carry out troubleshoot-
ing without turning starting switch ON.
R06 (male), R07 (male) Resistance
Between (1) – (2) 300 – 600 z
Between (3) – (4) Max. 1 z
Between (3) – (5) Min. 1 Mz
6
Defective starting motor
safety relay (Internal defect)
a Prepare with starting switch OFF, then turn starting switch to
START and carry out troubleshooting.
Safety relay terminal Voltage
Between B – E Power supply 20 – 30 V
Between R
(R19-2) – E
Generation input Max. 1 V
Between S
(R19-1) – E
Starting input 20 – 30 V
Between C (R28) – E Starting output 20 – 30 V
If power supply, generation input, and starting input are normal but
starting output is not normal, starting motor safety relay is defec-
tive.
7
Defective starting motor
(Internal defect)
a Prepare with starting switch OFF, then turn starting switch to
START and carry out troubleshooting.
Starting motor terminals Voltage
Between B – chassis
ground
Power supply 20 – 30 V
Between C –
chassis ground
Starting input 20 – 30 V
If power supply and starting input are normal but starting motor
does not turn, starting motor is defective.

Komatsu 80001 Specifications

General

Brand	Komatsu
Model	80001
Category	Excavators
Language	English