Komatsu PC200-8M0, Shop Manual, Page: 861 / 1254

SEN06138-00
PC200, 200LC, 220, 220LC-8M0 40-400
39
400 Troubleshooting of electrical system (E-mode)
E-21 Swing holding brake does not operate properly
E-21 Swing holding brake does not operate properly
Failure 1) When swing brake cancel switch is set to CANCEL position, machine cannot swing.
Related infor-
mation
q Signal of swing lock switch can be checked with monitoring function.
(Pump controller system code: 02200 Switch input 1)
Cause Procedure, measuring location, criteria and remarks
1 Defective fuse F01-1
If fuse F01-1 is broken, circuit probably has ground fault. In this case, perform trou-
bleshooting for cause 6 first.
2
Defective swing brake can-
cel switch (internal short cir-
cuit)
1. Turn starting switch to OFF position.
2. Disconnect connector S25 and connect T-adapters to male side.
Between S25 (male) (13)
and (14)
swing brake cancel switch:
Normal
Resistance Min. 1 M
z
swing brake cancel switch:
FREE
Resistance Max. 1
z
3
Defective diode array D01 or
D03 (internal short circuit)
1. Turn starting switch to OFF position.
2. Remove diode arrays D01 and D03, and connect T-adapters to male side.
a
Check the continuity in diode range.
Between D01 (male) (7) (+) and (3) (-) Continuity
Between D01 (male) (3) (+) and (7) (-) No continuity
Between D03 (male) (7) (+) and (3) (-) Continuity
Between D03 (male) (3) (+) and (7) (-) No continuity
4 Defective wiring harness
1. Turn starting switch to OFF position.
2. Disconnect connector V03 and connect T-adapters to female side.
3. Turn starting switch to ON position.
Between V03 (female) (1)
and (2)
swing brake cancel switch:
FREE
Voltage 20 to 30 V
swing brake cancel switch:
Normal
Voltage Max. 1 V
5
Open circuit in wiring har-
ness
(wire breakage or defective
contact of connector)
a
If no failure is found by check on cause 4, this check is not required.
1. Turn starting switch to OFF position.
2. Disconnect connectors V03 and S25 and connect T-adapters to each male side.
Between V03 (female) (1) and S25 (female) (14) Resistance Max. 1
z
Between V03 (female) (2) and C02 (female) (115) Resistance Max. 1
z
6
Ground fault in wiring har-
ness
(contact with ground circuit)
a
If no failure is found by check on cause 3, this check is not required.
1. Turn starting switch to OFF position.
2. Disconnect connectors S25, V03, D01 and D03, and connect T-adapters to
female side of V03.
Between V03 (female) (1) and ground Resistance Min. 1 M
z