Code [451/Ca451] Rail Press. Sensor High Error - Komatsu 114E-3 Series Shop Manual

SEN00460-01
E-39 Code [451/CA451] Rail Press. Sensor High Error
Error code Failure code
451
Contents of
• High voltage occurred in common rail pressure sensor.
trouble
Action of con-
• Limits output and continues operation.
troller
Problem that
• Engine speed or output drops.
appears on
• Engine does not start
machine
Related infor-
• Method of reproducing failure code: Starting switch ON.
mation
Defective sensor power sup-
1
ply 2 system
Defective common rail pres-
2
sure sensor
Hot short (Short circuit with 5
3 V, 24 V circuit) in wiring har-
ness
Possible causes
and standard
value in normal
state
Short circuit in wiring har-
4 ness (With another wiring
harness)
Defective wiring harness
5
connector
6 Defective engine controller
24
Trouble
CA451
Causes
Abnormally high level in common rail pressure sensor
Standard value in normal state/Remarks on troubleshooting
If failure code [CA227] is indicated simultaneously, carry out trouble-
shooting for it first.
a Prepare with starting switch OFF, then turn starting switch ON
and carry out troubleshooting.
FUEL RAIL PRESS
Between (3) – (1)
Voltage is measured with wiring harness connected. Accordingly, if
voltage is abnormal, check wiring harness and controller, too, for
another cause of trouble, and then judge.
a Prepare with starting switch OFF, then turn starting switch ON
and carry out troubleshooting.
Wiring harness between J1 (female) (25) –
FUEL RAIL PRESS (female) (2)
a Troubleshoot with starting switch OFF, then carry out trouble-
shooting without turning starting switch ON.
Wiring harness between J1 (female) (25) –
FUEL RAIL PRESS (female) (2) and J1
(female) (37) – FUEL RAIL PRESS (female)
(3)
Connecting parts among common rail pressure sensor, engine wir-
ing harness, and engine controller are suspected. Inspect them
directly.
• Loose connector, broken lock, broken seal
• Corrosive, bent, broken, forced-in, or extended pin
• Humidity in connector, entry of dirt or dust, poor insulation
a Prepare with starting switch OFF, then turn starting switch ON
and carry out troubleshooting.
J1
Between (37) – (47)
40 Troubleshooting
Power supply 4.75 – 5.25 V
Voltage
Resis-
tance
Power supply 4.75 – 5.25 V
114E-3 Series
1
Voltage
Max. 1 V
Min.
100 kz
Voltage