1. Failure Description

User Code	E15	Failure	Common Rail Low Pressure Failure ( Engine Controller System)
Fault Code	CA559
Failure Details	There is a low-pressure fault in common rail circuit
Controller Response	No particular response
Problem on Machine	The engine does not work or has difficulty starting; The exhaust turns black; Engine output drops.
Relevant Information	The common rail pressure can be checked with monitoring function; (Code: 36400 Common rail pressure) Method of reproducing the fault code: Start the engine.
Also Applicable to	PC200-8, PC220-8, PC200LC-8, PC220LC-8, etc.

2. Troubleshooting

The following are possible causes and detection methods:

Fuel Leaking Outside 

Detection method:  Check it directly. (Perform a visual inspection while the engine is idling at a low RPM.)

Before testing, learn about the fuel pressure diagnostic tools:

Fuel pressure diagnostic tool:

Symbol	Part Number	Product Name
F1	799-101-5002	Hydraulic pressure test kit
F1	790-261-1204	Digital hydraulic detector
F2	6732-81-3170	Coupling(10✖1.0mm-R1/8)
F2	6215-81-9710	O Ring
F3	799-401-2320	Hydraulic detector

 

Partial Failure of Low-Pressure Oil Circuit

Detection method:

1) Open the engine hood and take down the fuel pressure inspection plug (1) from the main fuel filter.

2) Install the connecting nipple [1] of the hydraulic pressure detector F1 and the joint F2 to the fuel pressure gauge [2].

★ Fuel pressure inspection plug should be: 10 ± 2 Nm {1 ± 0.2 kgm}

★ Fuel pressure gauge should be: 2.5 MPa {25 kg / cm²}

3) Run the engine at low idle speed, and measure the pressure of the low-pressure oil circuit.

★ If the engine fails to start, use the starter motor to initiate ignition and then measure fuel pressure. However, in order to prevent damage to the starter motor, avoid continuous usage and limit engine starting time within 20 seconds.

4) After taking measurements, remove the measuring tool and reinstall the previously removed components as indicated below.

Standard values: If the pressure of the low-pressure oil circuit is within the specified range, it is considered normal.

At low idle	0.5-0.3 MPa {5.1-13.3 kg/cm²}
When the engine starts	0.3-1.1 MPa {3.1-11.3 kg/cm²}

 

Pressure Limiter Failure

Detection method:

1) Open the engine hood and disconnect the fuel return hose (2) from the pressure limiter.

★ Install the sealing washer onto the connector bolt.

2) Reposition the removed connector bolt (3) and the end cap nut [1] of tester assembly G1 on the fuel return hose to prevent fuel leakage.

3) Install connector G3 to the common rail and connect the test hose [2] of tester assembly G1.

★ Lay the test hose flat to ensure smooth flow, and place its end to the oil pan.

4 ) Run the engine at low idle speed and use the measuring cylinder G4 to measure the fuel return amount within 1 minute.

5 ) After taking measurements, remove the measuring tool and reinstall the previously removed components.

★ Connecting bolt should be: 24 ± 4 Nm {2.4 ± 0.4 kgm}

Standard values:

★ If the leakage of the pressure limiter is within the following range, it can be considered normal.

At low idle

0 cc (no leak)

 

Injectors (including the top high-pressure pipeline) Failure

Detection method: When connecting the oil return hose of the pressure limiter, it is recommended to first confirm the normal fuel flow of the pressure limiter before proceeding with measuring the injector's fuel flow.

1) To measure the fuel return speed of the supply pump, you should set up a testing mode first.

During the measurement, the fuel will flow out from the supply pump. So, please make sure that the test hose end is placed in an oil pan.  

2) Detach the oil return hose (4) from the oil return unit.   

★ Install the sealing washer on the oil return hose.

3) Reinstall the connector bolts [3] of the pipe joint G2 to replace them. Then, connect the test hose [4].

★ Lay the test hose flat to ensure smooth flow and place the end in the oil pan.

★ The shape of the parts shown in the figure below is not exactly the same as PC200 and PC220-8.

4) Run the engine at low idle speed, and use a measuring cylinder G4 to measure oil return within 1 minute. 

★If the engine fails to start, use the starter motor to initiate ignition and then measure fuel pressure. However, in order to prevent damage to the starter motor, avoid continuous usage and limit the engine starting time within 20 seconds.

5 ) After taking measurements, remove the measuring tool and reinstall the previously removed components.

Standard values:

★ If the oil return volume of the injector is within the following range, it is considered normal.

At low idle	180 cc/min
When the engine starts	90 cc/min

 

Fuel Pump Failure

Detection method:

1) Open the engine hood and disconnect the fuel return hose (1) from the supply pump.

2) Install the connector G3 and the cover nut [1] of tester assembly G1 on the fuel return hose to prevent fuel leakage.

3) Connect the test hose [2] of the tester assembly G1 to the supply pump. 

★ Lay the test hose flat to ensure smooth flow and place the end in the oil pan.

4 ) Run the engine at low idle speed, use a measuring cylinder G4 to measure fuel return within 1 minute.

★If the engine fails to start, use the starter motor to initiate ignition and then measure fuel pressure. However, in order to prevent damage to the starter motor, avoid continuous usage and limit the engine starting time within 20 seconds.

5 ) After taking measurements, remove the measuring tool and reinstall the previously removed components.

★When measuring the fuel flow of the injector, no need to care about removed parts, but just ensure that the hose end is placed in the oil pan.

Standard values: If the oil return volume of the supply pump is within the following range, it is considered normal.

At low idle	1000 cc/min
When the engine starts	140 cc/min

 

3. Possible Solutions

If the problem is with the pressure limiter, you’re recommended to replace the Komatsu pressure relief valve 1110010028 / 6754-72-1220; 

• If the problem is with the fuel injector, you’re recommended to replace the Komatsu fuel injector 6754-11-3010 / 6754-11-3011 / 0445120231;     

• If the problem is with the fuel pump, you’re recommended to replace the Komatsu fuel injection pump 6754-71-1310 / 6754-72-1012. 

 

4. More Technical Support

If you need more information or further assistance, please feel free to let us know via live chat or email: service@sinocmp.com, we will reach out to you ASAP.

Related to:

Error Code List for Komatsu PC200-8, PC220-8 and PC220LC-8 Excavators