E-4 Defective Bucket Positioner Function And Cancellation - Komatsu WA250-6 Shop Manual

SEN03848-00

E-4 Defective bucket positioner function and cancellation

Contents of
• Bucket positioner does not function or cannot be cancelled due to defective bucket positioner proxim-
trouble
ity switch system, bucket PPC detent system and bucket detent relay system.
Related
information
Defective bucket leveler relay
1
(L114)
Possible
causes and
standard value
in normal state
Defective detent active relay
2
(L113)
3 Defective bucket PPC detent
18
40-400
Causes
a Prepare with starting switch OFF.
a Replace bucket leveler relay (L114) with normal relay.
a Operate bucket positioner with engine started.
Bucket positioner function is normal.
Bucket positioner does not function.
a Prepare with starting switch OFF, then carry out troubleshooting
without turning starting switch ON.
Between L114 (male) (1) and (2)
a Prepare with starting switch OFF.
a Solid part check.
a Applies impressed voltage between L114 (male) (1) – (2)
Between
L114
(male) (3)
and (5)
a Turn starting switch OFF.
a Replace detent active relay (L115) with normal relay.
a Operate boom kick-out with engine started.
Boom kick-out function is normal.
Boom kick-out does not function.
a Prepare with starting switch OFF, then carry out troubleshooting
without turning starting switch ON.
Between L115 (male) (1) and (2)
a Prepare with starting switch OFF.
a Solid part check.
a Applies impressed voltage between L115 (male) (1) – (2)
Between
L115
(male) (3)
and (5)
a Prepare with starting switch OFF, then carry out troubleshooting
without turning starting switch ON.
Between L37 (male) (1) and (2)
400 Troubleshooting of electrical system (E-mode)
E-4 Defective bucket positioner function and cancellation
—
Standard value in normal state/Remarks on troubleshooting
Applies 24V impressed voltage
between L114 (male) (1) – (2)
Does not apply voltage between
L114 (male) (1) – (2)
Applies 24V impressed voltage
between L115 (male) (1) – (2)
Does not apply voltage between
L115 (male) (1) – (2)
1
Defective relay L114.
Relay L114 is normal.
Resis- 200 – 400
z
tance
Resis-
Max. 1 z
tance
Resis-
Min. 1 Mz
tance
Defective relay L115.
Relay L115 is
normal.
Resis- 200 – 400
tance z
Resis-
Max. 1 z
tance
Resis-
Min. 1 Mz
tance
Resis-
30 – 50 z
tance
WA250, 250PZ-6