Komatsu PC88MR-10 Shop Manual page 778

40 Troubleshooting
Troubleshooting by failure code (Display of code)
No. Cause
Open circuit in wiring
harness
4
(wire breakage or
defective contact of
connector)
Ground fault in wiring
harness
5
(contact with ground
circuit)
Open circuit or hot short
circuit in wiring harness
6
(contact with 24 V
circuit)
Pump controller is
7
defective.
40-290
Procedure, measuring location, criteria, and remarks
ACC signal of starting switch (start of CAN communication is not
recognized)
1. Turn starting switch to OFF position, and set battery disconnect switch to
OFF position.
2. Disconnect connectors CM01, CP01, CE03 and insert T-adapters.
3. Turn battery disconnect switch to ON position, and turn starting switch to
ON position.
Between CM01 (10) and (3)
Voltage
Between CE03 (3) and (21)
Between CP01 (2) and each of (24), (43), and (80)
a If no failure is found by check on cause 3, this check is not required.
1. Turn starting switch to OFF position, and set battery disconnect switch to
OFF position.
2. Disconnect connectors CM02, CP01, J1 and J2, and connect T-adapters
to each female side.
Between CM02 (female) (11) and CP01 (female) (7)
Between CM02 (female) (12) and CP01 (female)
(26)
Resistance
Between CM02 (female) (11) and J1 (female) (8)
Between CM02 (female) (12) and J1 (female) (18)
1. Turn starting switch to OFF position, and set battery disconnect switch to
OFF position.
2. Disconnect connectors CM02, CP01, J1 and J2, and connect T-adapter to
female side of any one.
Between ground and any one of CP01 (female) (7),
CM02 (female) (10), (11), or J1 (female) (8)
Between J2 (female) (24) and ground
Resistance
Between ground and any one of CP01 (female)
(26), CM02 (female) (12), or J1 (female) (18)
Between J2 (female) (25) and ground
a If no failure (open circuit) is found by check on cause 3, measure voltage at
any one place in each case.
1. Turn starting switch to OFF position, and set battery disconnect switch to
OFF position.
2. Disconnect either of connectors CM02 and CP01, and connect T-adapter
to female side of connector disconnected.
3. Turn battery disconnect switch to ON position.
4. Turn starting switch to ON position.
a Do not take measurements at J1 or J2.
a Voltage of CAN H and CAN L is 2.5 ± 1 V including during communication,
so regard wiring harness as normal if measured voltage is 1 to 4 V.
Between ground and any one of CP01 (female) (7),
CM02 (female) (10), (11)
Voltage
Between ground and either of CP01 (female) (26)
and CM02 (female) (12)
If failure code [DA2RKR] is also displayed.
a Disconnect pump controller and engine controller one by one from CAN
communication line to determine which controller is defective.
1. Turn starting switch to OFF position, and set battery disconnect switch to
OFF position.
2. Disconnect pump controller (connector CP01).
3. Turn battery disconnect switch to ON position, and turn starting switch to
ON position.
Does either or both of failure codes [DA2RKR] and
[DB2RKR] disappear?
20 to 30 V
20 to 30 V
20 to 30 V
Max. 1 z
Max. 1 z
Max. 1 z
Max. 1 z
Min. 1 Mz
Min. 1 Mz
Min. 1 Mz
Min. 1 Mz
1 to 4 V
1 to 4 V
If YES, pump controller is
defective.
PC88MR-10