SRSC45H4 Fault Case

Basic Fault Information

Item	Content
Time	2025-11-24 10:16:23
Fault Type	Engine Fault
Equipment Serial Number	RS4504CE0131
Product Model	SRSC45H4
Business Unit	Port Machinery Business Unit
Product Group	20/Reach Stacker/Reach Stacker
Operating Hours	2271
Shutdown Fault	Yes
Operation Location	Chile
Public Element	Display
Service Order	5625090530

Fault Description

1. Unable to release the parking brake, and the entire vehicle cannot travel; 2. The display interface reports 6-7 engine fault codes, with engine speed limitation and torque limitation.

Fault Analysis, Troubleshooting Process and Fault Summary

I. Unable to Release the Parking Brake and the Entire Vehicle Cannot Travel

On-site Troubleshooting Process

1. Enter the display information query interface to check the parking and brake pressure values when starting the engine, which all show 0;
2. Measure the power supply lines of electrical components such as the parking accumulator solenoid valve and parking pressure sensor, all of which are 24V power supply, the power supply is normal, and electrical faults are ruled out;
3. Manually trigger the action of the parking accumulator solenoid valve, but the parking brake still cannot be released, ruling out the solenoid valve jamming fault;
4. Check the temperature of the hydraulic pump and hydraulic pipeline (no pressure gauge on site), the hydraulic pump temperature is normal, but the hydraulic pump outlet pipeline has no temperature;
5. Based on the above phenomena, it is judged that the failure to release the parking brake and no pressure display are caused by no hydraulic oil delivery;
6. Remove the hydraulic pump inlet pipeline and find that the plug on the inlet pipeline is not removed, causing the hydraulic pump to be unable to suck oil.

Cause Analysis

Combined with the previous situation of the equipment (the engine and gearbox were overhauled before the fault), this problem was caused by the service technician forgetting to remove the plug of the oil pipeline when installing the hydraulic pump pipeline.

II. The Display Interface Reports 6-7 Engine Fault Codes, with Engine Speed Limitation and Torque Limitation

On-site Troubleshooting Process

1. Enter the fault information query interface to view the engine fault codes: 3226-9/5743-9/1761-9/3031-9/3364-9/1569-31, etc.;
2. According to the fault code query, all are after-treatment system-related fault codes, including communication faults of the nitrogen oxide sensor and urea level sensor;
3. Check the CAN lines and 24V lines of each sensor on the urea, DOC, and SCR modules. The CAN line voltage is 2.3V (normal), and the power supply lines of the urea and DOC modules are 24V (abnormal);
4. Check the after-treatment related fuses and after-treatment wiring harness. The fuses are intact, and it is found that both the 0# ground wire and 108# power wire of the after-treatment wiring harness are broken, leading to abnormal module power supply and generating fault codes;
5. Reconnect the wiring harness and check the fault codes. The number of codes is reduced to 3, which are 1569-31/5571-0/157-18 respectively. These codes indicate low fuel pressure;
6. Check whether the fuel filter is clogged and the fuel pipeline is unobstructed. Both the filter and pipeline are normal, and further troubleshoot the fuel pump and high-pressure common rail sensor;
7. Temporarily replace the fuel actuator and pressure sensor with stock accessories, but the fault codes still exist. Continue to troubleshoot whether there are faults in the high-pressure fuel pump and injectors;
8. Check the injector return pipeline after starting the engine. The return oil volume is huge at idle speed and acceleration, and the pressure cannot be established, leading to the fault code;
9. Finally, disassemble and supply parts to replace 6 injectors for testing. There are no fault codes and no torque limitation, and the gearbox is calibrated at the same time.

Cause Analysis

Due to the overhaul of the gearbox of the equipment, the fuel quality deteriorated after being parked for a long time, resulting in injector damage. (According to Cummins after-sales: the normal fuel injector return oil volume is in the form of dripping when starting the machine, and the return oil volume is slightly larger when accelerating, so it is judged that the injector is faulty.)

Summary

This fault case involves the SRSC45H4 reach stacker, which has two main faults: inability to release the parking brake and engine speed/torque limitation with multiple fault codes. For the parking brake fault, on-site troubleshooting found that the plug of the hydraulic pump inlet pipeline was not removed during the post-overhaul installation, resulting in the hydraulic pump being unable to suck oil and no oil delivery. For the engine fault, the initial fault codes were related to the after-treatment system, caused by the breakage of the after-treatment wiring harness; after repairing the wiring harness, the remaining fault codes indicated low fuel pressure, which was finally confirmed to be caused by injector damage due to deteriorated fuel quality during long-term parking. After replacing the injectors and calibrating the gearbox, the equipment returned to normal. This case reminds that attention should be paid to the completeness of pipeline installation during equipment overhaul, and fuel quality should be checked regularly when the equipment is parked for a long time to avoid component damage.