Komatsu PC88MR-10 Shop Manual page 775

No. Cause
Ground fault in wiring
harness
7
(contact with ground
circuit)
Open circuit or hot short
circuit in wiring harness
8
(contact with 24 V
circuit)
Defective engine
controller, pump
9 controller, air
conditioner unit, or
KOMTRAX terminal
Defective engine
10
controller
Defective machine
11
monitor
PC88MR-10
Procedure, measuring location, criteria, and remarks
a If no failure (open circuit) is found by check on cause 5, 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 of CP01 (female) (45),
CM02 (female) (7), (8) and CE03 (female) (17)
Resistance
Between ground and any of CP01 (female) (64),
CM02 (female) (9) and CE03 (female) (18)
a If no failure (open circuit) is found by check on cause 5, 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 any of CM02 (8), CP01 (45),
CK01 (10), AC01 (2) and CE03 (17)
Voltage
Between ground and any of CM02 (9), CP01 (64),
CK01 (11), AC01 (1) and CE03 (18)
If all 4 failure codes [DA2QKR], [DB2QKR], [D8AQKR], and [DAZQKR] are
displayed
a To identify defective controller, repeat following steps 1. to 3. to disconnect
controllers one by one from CAN communication line .
1. Turn starting switch to OFF position, and set battery disconnect switch to
OFF position.
2. Disconnect CAN communication connector of engine controller (connector
CE03), pump controller (connector CP01), air conditioner unit (connector
AC01), and KOMTRAX terminal (connector CK01) one by one in turn.
3. Turn battery disconnect switch to ON position, turn starting switch to ON
position, then perform troubleshooting.
4. Return to step 1 to check next connector.
Has the number of displayed failure codes
decreased from 4?
If no failure is found by above checks, engine controller is defective.
(Since this is an internal defect, troubleshooting cannot be performed.)
If no failure is found by above checks, machine monitor is defective.
(Since this is an internal defect, troubleshooting cannot be performed.)
40 Troubleshooting
Troubleshooting by failure code (Display of code)
controller is defective.
Min. 1 Mz
Min. 1 Mz
1 to 4 V
1 to 4 V
If YES, disconnected
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