Komatsu PC88MR-10 Shop Manual page 668

40 Troubleshooting
Troubleshooting by failure code (Display of code)
No. Cause
Hot short circuit in wiring
5
harness
Defective common rail
pressure sensor
6
(improper input voltage to
engine controller)
Defective engine controller
7
Circuit diagram related to common rail pressure sensor
40-180
Procedure, measuring location, criteria and remarks
1. Turn starting switch to OFF position.
2. Disconnect connector PFUEL and J2.
3. Connect T-adapter to either female side.
4. Turn starting switch to ON position (with connector PFUEL
disconnected).
a Pin (55) of connector J2 is connected to 5 V circuit via resistor inside
engine controller.
Between PFUEL (2) and (3), or J2 (55) and
Voltage
(21)
a If no failure is found by checks on causes 1 to 5 and if failure is
found by check on cause 6, sensor is defective.
1. Turn starting switch to OFF position.
2. Insert T-adapters into connector PFUEL and J2.
3. Turn starting switch to ON position.
Between PFUEL (2) and (3), or J2
Voltage
(55) and (21)
If no failure is found by above checks, engine controller is defective.
(Since this is an internal defect, troubleshooting cannot be performed.)
Approx. 5 V
Sensor
0.2 to 4.6 V
output
PC88MR-10