Komatsu PC88MR-10 Shop Manual page 770

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)
40-282
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 to be measured and insert T-adapters into them.
3. Turn battery disconnect switch to ON position, and turn starting switch to
ON position.
Between CM01 (10) and (3)
Between CE03 (3) and (21)
Voltage
Between AC02 (4) and (1)
Between CK02 (3) and (1)
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 related connectors and connect T-adapters to female side of
connectors to be measured.
Between CM02 (female) (8) and CP01 (female)
(45)
Between CM02 (female) (9) and CP01 (female)
(64)
Between CM02 (female) (8) and CE03 (female)
(17)
Between CM02 (female) (9) and CE03 (female)
(18)
Between CM02 (female) (8) and AC01 (female) (9)
Resistance
Between CM02 (female) (9) and AC01 (female)
(10)
Between CM02 (female) (8) and CK01 (female)
(10)
Between CM02 (female) (9) and CK01 (female)
(11)
Between CE03 (female) (17) and K02 (female) (A)
Between CE03 (female) (18) and K02 (female) (B)
a If no failure (open circuit) is found by check on cause 3, measure
resistance at any one place in each case.
1. Turn starting switch to OFF position, and set battery disconnect switch to
OFF position.
2. Disconnect related connectors and connect T-adapters to female side of
connectors to be measured.
Between ground and any point in CP01 (female)
(45), CM02 (female) (7), (8) or CE03 (female) (17)
Resistance
Between ground and any point in CP01 (female)
(64), CM02 (female) (9) or CE03 (female) (18)
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. Insert T-adapters into connectors to be measured.
3. Turn battery disconnect switch to ON position.
4. Turn starting switch to ON position.
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 either of CM02 (8), CP01
(45), CK01 (10), AC01 (2) and CE03 (17).
Voltage
Between ground and either of CM02 (9), CP01
(64), CK01 (11), AC01 (1) and CE03 (18).
20 to 30 V
20 to 30 V
20 to 30 V
20 to 30 V
Max. 1 z
Max. 1 z
Max. 1 z
Max. 1 z
Max. 1 z
Max. 1 z
Max. 1 z
Max. 1 z
Max. 1 z
Max. 1 z
Min. 1 Mz
Min. 1 Mz
1 to 4 V
1 to 4 V
PC88MR-10