Failure Code [Dxh7Kz] Reverse Solenoid: Disconnection/Hot Short - Komatsu WA250-6 Shop Manual

SEN03847-00

Failure code [DXH7KZ] Reverse solenoid: Disconnection/Hot short

Action code Failure code
E03 DXH7KZ
• Reverse solenoid is not turned ON (HST pressure selector relay does not operate) (when there is
Contents of
disconnection).
trouble
• Reverse solenoid cannot be turned OFF (Where there is hot short).
Action of • Turns output to reverse solenoid OFF.
controller
• Turns the centralized warning lamp and alarm buzzer ON.
• Machine does not travel in reverse (when there is disconnection).
Problem that
appears on
• Machine may start in reverse suddenly (when there is hot short).
machine
• Gear is not set in neutral (when there is hot short).
• Output state to HST pump R (Reverse) solenoid of HST controller can be checked with monitoring
Related
function.
information
(Monitoring code: HST – 40980 – D-OUT-19)
Defective reverse solenoid
1
(Internal defect)
Defective diode
2
(Internal defect)
Defective FR pressure select
3
relay (Internal defect)
Possible causes
and standard
value in normal
state
Disconnection in wiring har-
ness (Disconnection in wiring
4
or defective contact in con-
nector)
Hot short (Contact with 24V
5
circuit) in wiring harness
6 Defective HST controller
20
40-370
Failure code [DXH7KZ] Reverse solenoid: Disconnection/Hot short
Reverse solenoid: Disconnection/Hot short
Trouble
(HST controller system)
Causes
a Prepare with starting switch OFF, then carry out troubleshooting
without turning starting switch ON.
a Prepare with starting switch OFF, then carry out troubleshooting
without turning starting switch ON.
(See Testing and adjusting, "Test procedure for diode".)
Between T01B (male) (2) – (1)
a Prepare with starting switch OFF, then turn starting switch ON
and carry out troubleshooting.
Replace FR pressure
select relay (L101)
with another relay
a Prepare with starting switch OFF, then carry out troubleshooting
without turning starting switch ON.
Between L101 (male) (5) – (6)
a Prepare with starting switch OFF, then carry out troubleshooting
without turning starting switch ON.
Wiring harness between HST (female) (20) –
T01 (female) (3)
Wiring harness between T01 (female) (4) –
ground
a Prepare with starting switch OFF, then turn starting switch ON
and carry out troubleshooting.
Between wiring harness HST (female) (20) –
T01 (female) (3) and ground
a Prepare with starting switch OFF, then start engine and release
parking brake, and carry out troubleshooting.
370 Troubleshooting by failure code (Display of code), Part 7
Standard value in normal state/Remarks on troubleshooting
T01 (male)
Between (3) – (4)
Between (3), (4) – ground
Condition becomes
normal
Condition does not
become normal
Directional lever
HST
R (Reverse)
Between (20) –
ground
Other than above
Resistance
15 – 30 z
Min. 1 Mz
No continuity
Relay (L101) is
defective
Relay (L101) is
normal
Resis-
tance
Resis-
tance
Resis-
tance
Voltage
Voltage
position
20 – 30 V
Max. 1 V
WA250, 250PZ-6
1
200 –
400 z
Max. 1 z
Max. 1 z
Max. 1 V