Direct answer
Missing hydraulic information on a 6225N display is a data complaint, not proof of a failed controller. Preserve the screen message and determine whether information is missing from one page, several systems or the entire display before requesting electrical diagnosis.
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.
Document the display state
Photograph the full screen, including units, warning symbols and any communication messages. Record whether engine speed, temperatures and operating hours still appear. Note whether the problem began after battery work, washing, harness repair or a controller change.
Identify the installed electronics
Send the complete machine serial number and externally accessible display/controller labels. Do not identify controller compatibility from “6225N” alone. A replacement may require a matching hardware version, software and configuration.
Keep network testing specific
Ask the technician to use the correct wiring diagram and record power, ground and communication tests with the circuit state and test method. A single average voltage is not a complete CAN communication test. Do not apply generic pin numbers, resistance limits or conductive products to connectors.
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
Should I order a controller because all hydraulic values disappeared?
Not from that observation alone. Obtain a documented diagnosis that separates display, power supply, harness, network and controller issues.
What if the machine still moves normally?
Report this separately from the missing data. It does not establish that the display or the control system is safe to ignore.
Sources and scope of evidence
- Lonking manufacturer and service contact — 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
- How to Read a Construction Machine Model and Serial Plate
- 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.
