Komatsu PC58UU-3 User Manual

PC58UU-3 20-337
TROUBLESHOOTING
b) Engine control system does not operate at all or it operates for a moment and does not operate any
more
(Abnormal speed or insufficient stroke of cable)
Cause Remedy
1
Bending or interference of
fuel control linkage or defec-
tive operation of governor
lever
• Disconnect cable from motor
and rotate it with hand.
Does fuel control system move
smoothly?
NO
Replace
YES
2
Disconnection or defective
contact in wiring harness
between fuse FU4 – G3
(female) (1), (11)
• 10 – 15 V
• Turn starting switch ON.
Is resistance between G3 (1), (11) –
chassis ground normal?
NO
Repair or
replace
YES
3
• Replace R3, R4, or R5 with
normal relay.
When R3, R4, or R5 is replaced, does
engine control system operate nor-
mally?
NO
Defective relay R3, R4, or R5 Replace
4
Disconnection or defective
contact in wiring harness
between R3 (female) (4) –
chassis ground or R4
(female) (4) – chassis ground
• Max. 1 z
• Turn starting switch OFF.
• Disconnect R3 and R4.
Is resistance between R3 (female) (4) –
chassis ground or R4 (female) (4) chas-
sis ground normal?
NO
Repair or
replace
YES
5
Disconnection or defective
contact in wiring harness
between R3 (female) (5) –
R4 (female) (5) – R5 (female)
(5)
• Max. 1 z
• Turn starting switch OFF.
• Disconnect R3, R4, and R5.
Is resistance between R3 (female) (5) –
R4 (female) (5) – R5 (female) (5) nor-
mal?
NO
Repair or
replace
YES
• Max. 1 z
• Turn starting switch OFF.
• Disconnect F22, R3, R4, and
R5.
6
Disconnection or defective
contact in wiring harness
between F22 (female) (4) –
R3 (female) (3), F22 (female)
(1) – R4 (female) (3), or F22
(female) (2) – R5 (female) (3)
Is resistance between F22 (female) (4)
– R3 (female) (3), F22 (female) (1) – R4
(female) (3), or F22 (female) (2) – R5
(female) (3) normal?
NO
Repair or
replace
YES
•Min. 1 Mz
• Turn starting switch OFF.
• Disconnect F22, R3, R4, and
R5.
7
Short circuit with chassis
ground in wiring harness
between F22 (female) (4) –
R3 (female) (3), F22 (female)
(1) – R4 (female) (3), or F22
(female) (2) – R5 (female) (3)
Is resistance between F22 (female) (4),
F22 (female) (1), F22 (female) (2) –
chassis ground normal?
NO
Repair or
replace
YES
• Between wiring harnesses:
Max. 1 z
• Between F22 (female) (5), F22
(female) (6) – chassis:
Min. 1 Mz
• Turn starting switch OFF.
• Disconnect F22 and G3.
8
Disconnection, defective con-
tact, or short circuit with
chassis ground in wiring har-
ness between F22 (female)
(5) – G3 (female) (19) or F22
(female) (6) – G3 (female)
(29)
Is resistance between F22 (female) (5)
– G3 (female) (19), F22 (female) (6) –
G3 (female) (29), or F22 (female) (5),
F22 (female) (6) – chassis normal?
NO
Repair or
replace
9
Is voltage between each terminal of
accelerator motor and chassis as
shown in Table 1?
NO
Defective accelerator motor Replace
Defective controller Replace
E-18
(6)

Komatsu PC58UU-3 Specifications

General

Brand	Komatsu
Model	PC58UU-3
Category	Construction Equipment
Language	English