Direct answer
If the engine stalls during combined functions and an EGR message is present, keep both observations in the service record. Do not dismiss the engine message or assume a pump regulator is the cause before the exact engine and hydraulic configuration are assessed.
Scope and safety
This is a symptom-recording and service-handoff guide, not a procedure for testing or adjusting the machine. Follow the exact machine manual and displayed safety instructions. Keep clear of moving equipment and suspected pressurized leaks. Shutdown alone may not remove stored pressure; hydraulic work and attachment support require the correct procedure and qualified personnel.
Preserve messages before changes
Photograph the full fault message and record whether it appeared before, during or after the stall. Include the complete machine and engine identification. Do not clear the history as the first diagnostic step.
Describe the combined action
State which functions were being used, the attachment and work mode, and whether the symptom also occurred with a single function. Use existing observations; do not repeatedly stall the engine to gather data.
Ask for coordinated service findings
The service provider should identify the applicable engine and hydraulic procedures and explain the evidence for any proposed repair. Do not treat PC, LS and pump power control as interchangeable valve names. Regulator adjustments need the specified procedure and instruments.
Service handoff record
| Record | Information to supply |
|---|---|
| Identification | Full machine model and serial; engine or attachment identity where relevant. |
| Complaint | The affected function, direction, timing and original screen message. |
| History | Recent service, changed parts and existing test reports; mark missing information as unknown. |
| Diagnosis | Technician’s confirmed component, applicable manual reference and repair scope. |
Frequently asked questions
Can I ignore the EGR message because the stall happens under hydraulic work?
No. Preserve it for the service assessment alongside the operating symptom.
Should I order a regulator immediately?
First obtain a confirmed diagnosis and the installed pump/regulator identification; the symptom alone does not select a part.
Sources and scope of evidence
- Sumitomo service and support — manufacturer documentation or support access; obtain the reference for your exact machine.
- Caterpillar hydraulic hose inspection and pressure safety — general hydraulic inspection and stored-pressure safety.
These public sources provide documentation/support routes and general safety context. They do not verify a model-specific fault-code definition, pressure setting or repair case. This guide therefore supplies no such specifications. Source links checked 14 September 2026.
Related guides
- Excavator Hydraulic Pump Failure Symptoms and Next Checks
- How to Check Parts Fitment Before an International Order
Parts identification after diagnosis
Danch Machinery supplies genuine parts. Send the confirmed part number, machine serial number and clear identification photographs for an availability and fitment inquiry. A symptom description does not establish fitment or current stock.
Request a parts identification check
About this guide
Published by Danch Machinery as general parts-identification and service-planning information. It is not a signed technical inspection or a machine-specific repair approval. Refer to the sources and scope stated in the article; confirm service procedures and fitment with the current manufacturer documentation for the exact machine.
Machine configurations and service requirements can differ by model, serial number and market. Confirm procedures and fitment with the current manufacturer documentation for your exact machine.
