Komatsu 75001, Руководство по ремонту

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SEN03843-00
40-330
22
WA250, 250PZ-6
330 Troubleshooting by failure code (Display of code), Part 3
Failure code [CA449] Common rail pressure high error 2
Failure code [CA449] Common rail pressure high error 2
1
Action code Failure code
Trouble
Common rail pressure high error 2
(Engine controller system)
E03 CA449
Contents of
trouble
• Voltage (2) in common rail circuit is abnormally high.
Action of
controller
• Limits output and continues operation (limits common rail pressure).
• Turns the centralized warning lamp and alarm buzzer ON.
Problem that
appears on
machine
• Engine sound becomes larger under no load or light load.
• Engine output drops.
Related
information
• The input state (common rail pressure) from the common rail pressure sensor can be checked with
the monitoring function (Code: ENGINE, 36400, RAIL PRESS).
• The input state (voltage) from the common rail pressure sensor can be checked with the monitoring
function (Code: ENGINE, 36402, RAIL PRESS).
• Method of reproducing failure code: Start engine
Possible causes
and standard
value in normal
state
Causes Standard value in normal state/Remarks on troubleshooting
1 Defect in related system
• If another code is displayed, carry out troubleshooting for it.
2 Air in low-pressure circuit
Commingling of air with the low pressure circuit is suspected.
Inspect the circuit directly in the following procedure.
1) Remove the pressure pickup plug (outlet side) of the fuel main fil-
ter.
2) Operate the feed pump of the fuel pre-filter.
3) Inspect leakage of fuel and air from the pressure pickup plug.
3
Defective fuel return circuit
device
a For check of pressure in fuel return circuit, see Testing and
adjusting, “Testing fuel pressure”.
Fuel circuit pressure At low idle or cranking
Max. 0.02 MPa
{Max. 0.19 kg/cm
2
}
4
Defective common rail pres-
sure sensor
a Prepare with starting switch ON, then carry out troubleshooting
without turning starting switch OFF.
Monitoring code
(Machine monitor)
Monitoring information
Code: 36400,
RAIL PRESS
Condition when
engine stopped 0 – 0.39 MPa
{0 – 4 kg/cm
2
}
5 Defective pressure limiter
For testing of leakage from pressure limiter, see Testing and adjust-
ing, “Testing leakage from pressure limiter and return rate from
injector”.
Leakage from pres-
sure limiter
At low idle 0 cc (No leakage)
6 Defective supply pump If causes 1 – 5 are not detected, supply pump may be defective.