Troubleshooting Hitachi 450 Excavator Error 636-2: Causes, Solutions

[MikePhua]

Introduction: Understanding Error 636-2 on Hitachi 450 Excavators
The Hitachi 450 excavator is a powerful machine used in various industries, including construction, mining, and demolition. As with all advanced machinery, the Hitachi 450 is equipped with an onboard diagnostic system that alerts operators to potential issues through error codes. One such code that may appear is Error 636-2, which can leave operators wondering about the nature of the problem and how to resolve it.
Error 636-2 typically refers to a sensor or hydraulic system issue, and like other diagnostic codes, it needs to be addressed promptly to avoid further complications and downtime. In this article, we will explore the possible causes of Error 636-2, how to diagnose the issue, and steps to clear the code effectively.
What Does Error 636-2 Indicate?

1. Sensor Malfunction:
   Error 636-2 is most commonly linked to a sensor malfunction in the excavator's hydraulic system. The Hitachi 450 excavator relies heavily on various sensors to monitor fluid pressure, temperature, and other critical hydraulic parameters. If any of these sensors fail to provide accurate readings or malfunction, the system triggers an error code like 636-2. Typically, this could involve the pressure sensor or a related hydraulic component.
   
2. Hydraulic Pressure Problems:
   Another potential cause of Error 636-2 is an issue with the hydraulic pressure. Low or inconsistent hydraulic pressure can affect the performance of the excavator’s boom, arm, and bucket. This pressure issue could arise from a clogged hydraulic filter, leaks in the hydraulic lines, or a faulty hydraulic pump. If the system detects that hydraulic pressure is outside of normal operating parameters, it may trigger an error code.
   
3. Wiring or Connection Issues:
   A less common but still possible cause of Error 636-2 is a problem with the wiring or connections to the affected sensor. Worn-out or damaged wiring could lead to intermittent sensor readings, which the diagnostic system interprets as an error. These issues may require a thorough inspection of the sensor wiring and connections.
   
4. Software Glitch:
   Occasionally, the issue may not be physical but a result of a software glitch or miscommunication between the control unit and the sensors. This can happen due to system updates or incorrect calibration of the sensors. A software reset may be needed in such cases.
   

Steps to Diagnose and Resolve Error 636-2

1. Check the Hydraulic System:
   The first step in diagnosing Error 636-2 is to inspect the hydraulic system. Check the hydraulic fluid levels and ensure they are within the recommended range. Low hydraulic fluid can cause pressure fluctuations, which might trigger error codes. If the fluid level is fine, inspect the hydraulic filter for blockages or signs of contamination, as a clogged filter can cause irregular pressure.
   
2. Inspect Hydraulic Lines and Components:
   Look for any leaks or damage in the hydraulic lines, fittings, or hoses. Leaks can cause pressure loss, leading to error codes. Also, examine the hydraulic pump and pressure relief valves to ensure they are functioning correctly. If any hydraulic components are worn or damaged, replacing them should eliminate the error.
   
3. Examine the Sensors:
   Since Error 636-2 is most commonly linked to a sensor malfunction, the next step is to check the pressure sensor and its wiring. Look for corrosion, loose connections, or damaged wiring. If you notice any issues with the wiring or the sensor itself, replacing the faulty component is likely the best solution. Use a multimeter to test the sensor’s electrical connections and confirm whether it is providing accurate readings.
   
4. Perform a System Reset:
   If the hydraulic system and sensors seem to be in good condition, the issue might be due to a software glitch. In such cases, you may be able to resolve the issue by performing a system reset. This can usually be done through the machine’s control panel by following specific reset procedures outlined in the operator’s manual. Sometimes, simply turning the machine off and then on again can clear temporary faults.
   
5. Consult Diagnostic Tools:
   For more complex problems or if the error persists after basic troubleshooting, use an advanced diagnostic tool compatible with Hitachi excavators. These tools can read the error code in greater detail and provide more precise information on what’s causing the issue. Diagnostic tools can also help reset the error code once the issue has been fixed.
   

Clearing the 636-2 Error Code
Once the underlying issue causing Error 636-2 has been resolved, clearing the error code is the next step. The process for clearing the error code typically involves the following:

1. Manual Reset:
   After fixing the sensor or hydraulic issue, turn off the excavator and wait for a few minutes. Then, restart the machine. In many cases, the error code will clear automatically after a reset.
   
2. Diagnostic Tool Reset:
   If the manual reset does not work, use the diagnostic tool to clear the error code. These tools allow you to access the excavator’s computer system and reset error codes without needing to turn off the machine. Follow the tool’s instructions to clear the code.
   
3. Check for Recurrence:
   After clearing the error code, monitor the excavator to see if the error reappears. If the issue has been successfully fixed, the code should not reappear. If the error persists, further investigation may be required to determine whether there is an ongoing fault in the system.
   

Preventing Future Errors: Maintenance Tips for Hitachi 450 Excavators

1. Regular Hydraulic System Checks:
   The most effective way to avoid hydraulic-related errors is to perform regular checks of the hydraulic system. Regularly check the fluid levels, inspect the hoses for leaks, and replace filters as necessary. Keeping the hydraulic system clean and well-maintained will prevent many common issues, including Error 636-2.
   
2. Routine Sensor Calibration:
   Sensors play a critical role in ensuring smooth operation. Routine calibration and maintenance can help prevent sensor-related issues from occurring. If you notice any inconsistencies with sensor readings, address them immediately to avoid errors in the future.
   
3. Wiring Inspections:
   Regularly inspect the wiring and connections associated with sensors and hydraulic components. Replace any worn or damaged wiring before it leads to sensor malfunctions or error codes.
   
4. Software Updates:
   Ensure that your Hitachi 450’s software is up to date. Manufacturers occasionally release software updates that address known bugs and improve system stability. Check with your dealer or Hitachi service center for any updates that could improve your machine’s performance.
   

Conclusion: Resolving and Preventing Hitachi 450 Excavator Error 636-2
Error 636-2 on the Hitachi 450 excavator is often related to hydraulic pressure issues, sensor malfunctions, or wiring problems. By systematically diagnosing the issue, inspecting the hydraulic components, and checking the sensors, you can resolve the error and clear the code. Regular maintenance, including checking hydraulic fluid, calibrating sensors, and inspecting wiring, can prevent the recurrence of this error.
If you're not comfortable performing these tasks yourself, it’s always a good idea to consult a professional or Hitachi service technician who can provide in-depth support and ensure that your excavator is operating at its best. By addressing the root causes of the error and maintaining your machine properly, you can minimize downtime and maximize productivity on your projects.