Komatsu PC200-8M0, Shop Manual

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SEN06134-00
PC200, 200LC, 220, 220LC-8M0 40-302
31
302 Troubleshooting by failure code, Part 2
Failure code [CA449] Rail Press Very High Error
Failure code [CA449] Rail Press Very High Error
Action
level
Failure code
Failure
Common Rail Pressure Very High Error
(Engine controller system)
L03 CA449
Detail of failure q High pressure error (2) occurs in common rail circuit.
Action of con-
troller
q
Restricts engine output and allows engine to run.
Problem on
machine
q
Engine sound becomes large when no or light load is applied.
q
Engine output lowers.
Related infor-
mation
q Common rail pressure can be checked with monitoring function.
(Code:
36400 Common rail pressure)
q Method of reproducing failure code: Start engine.
Cause Procedure, measuring location, criteria and remarks
1 Defect in related system If another failure code is displayed, perform troubleshooting for it.
2 Air in low pressure circuit
Air may be in low-pressure circuit. Check it directly according to following pro-
cedure.
1. Remove fuel pressure pickup port plug (outlet side) of fuel main filter.
2. Operate feed pump of fuel pre-filter.
3. Check fuel and air from pressure pickup plug for leakage level.
3 Defect in fuel return circuit parts
a
For check of pressure in fuel return circuit, see Testing and adjusting, "Test-
ing fuel pressure".
Fuel return circuit pres-
sure
Engine at low idle or
cranking
Max. 0.02 MPa
{Max. 0.19 kg/cm
2
}
4
Defective common rail pressure
sensor system
Perform troubleshooting for failure codes [ CA451 ] and [ CA452 ]
5 Defective pressure limiter
a
For check of leakage from pressure limiter, see "Checking fuel return rate
and leakage" in Testing and adjusting.
Leakage from pressure
limiter
At low idle 0 cc (no leakage)
6 Defective supply pump If no failure is found by above checks, supply pump may be defective.