Komatsu PC200-8M0, Shop Manual

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304 Troubleshooting by failure code, Part 4
Failure code [DW45KB] Swing Brake Sol Short Circuit
40-304
42
PC200, 200LC, 220, 220LC-8M0
SEN06136-00
Failure code [DW45KB] Swing Brake Sol Short Circuit
Action
level
Failure code
Failure
Swing Brake Solenoid Short Circuit
(Pump controller system)
L03 DW45KB
Detail of failure
q
Abnormal current flows when pump controller drives swing holding brake solenoid, so pump con-
troller determines that short circuit exists in swing holding brake solenoid circuit.
Action of con-
troller
q
Stops driving swing holding brake solenoid.
q
Even if cause of failure disappears, machine does not become normal until starting switch is turned
to OFF position.
Problem on
machine
q
Upper structure does not swing (swing holding brake is not released).
Related infor-
mation
q
If solenoid and wiring harness are normal, swing operation is possible by setting swing brake can-
cel switch to RELEASE position. (However, swing holding brake is not released while upper struc-
ture is stopped. swing holding brake continues to be applied.)
q
Keep swing lock switch in OFF position and swing brake cancel switch in RELEASE position during
troubleshooting. When starting switch is turned to ON position in this condition, normally current
can flow in swing holding brake solenoid circuit and brake can be released.
q
Controller command (ON/OFF) to swing holding brake solenoid can be checked with monitoring
function. (Code: 02300 Solenoid 1)
q
Method of reproducing failure code: Turn starting switch to ON position.
q
swing holding brake solenoid circuit is powered from pin (101) of pump controller connector C02 or
pin (1) of fuse box F01.
Cause Procedure, measuring location, criteria and remarks
1
Blown fuse No. 1 (right top fuse) in
fuse box F01 Even if fuse is blown, perform troubleshooting according to following steps to
identify cause.
2
Defective swing holding brake
solenoid
1. Turn starting switch to OFF position.
2. Disconnect connector V03, and connect T-adapters to male side.
Between V03 (male) (1) and (2) Resistance 20 to 60
z
Between V03 (male) (1) and ground Resistance Min. 1 M
z
3 Defective diode array D01 or D03
1. Turn starting switch to OFF position.
2. Remove diode arrays D01 and D03, and connect T-adapters to each male
side.
a
Check the continuity in diode range.
Between D01 (male) (3) (+) and (7) (-) No continuity
Between D01 (male) (7) (+) and (3) (-) Continuity
Between D03 (male) (3) (+) and (7) (-) No continuity
Between D03 (male) (7) (+) and (3) (-) Continuity
4
Ground fault in wiring harness
(contact with ground circuit)
1. Turn starting switch to OFF position.
2. Remove fuse No.1 (right top, 10 A) in fuse box F01 and diode D01.
3. Disconnect connectors C02, D01 and V03.
4. Connect T-adapters to female sides of connectors C02 and D01.
Between C02 (female) (101) and ground Resistance Min. 1 M
z
Between D01 (female) (3) and ground Resistance Min. 1 M
z
5 Short circuit in wiring harness
1. Turn starting switch to OFF position.
2. Remove fuse No.1 (right top, 10 A) in fuse box F01 and diode D01.
3. Disconnect connector C02.
4. Connect T-adapters to female sides of connectors D01 and C02.
a
Check the swing lock switch OFF position.
Between D01 (female) (3) and C02 (female) (115)
or (117) or (120)
a
Swing brake solenoid coil resistance.
Resistance 20 to 60
z
6 Defective pump controller
If no failure is found by above checks, pump controller is defective. (Since this
is an internal defect, troubleshooting cannot be performed.)