What does Yaskawa GA800 E40 Fault - Causes & Fix mean?

E40 is not documented in standard GA800 manuals. Confirm the exact code on the display and check wiring, option cards, and control board.

How do I fix Yaskawa GA800 E40 Fault - Causes & Fix?

Work through the step-by-step fix below. Start with the quick reset and the most common cause, then check the specific part this guide points to. Most fixes need only basic hand tools and the right replacement part.

Can I keep using my Yaskawa appliance with GA800 showing?

Usually not. Yaskawa appliances show this error when a part or safety circuit is out of range, so running it can stop the cycle or make the problem worse. Diagnose and clear the error before normal use.

What part is most commonly replaced for Yaskawa GA800 E40 Fault - Causes & Fix?

The parts that most often fix Yaskawa GA800 E40 Fault - Causes & Fix are listed in the parts section of this guide. Match the part to your exact model and serial number before you buy.

Is Yaskawa GA800 E40 Fault - Causes & Fix a DIY repair or do I need a technician?

Many fixes are DIY-friendly with basic tools, such as door switches, drain pumps, water inlet valves, thermostats, heating elements, and filters. Sealed-system, refrigerant, gas, or high-voltage work should go to a licensed technician for safety.

Yaskawa GA800 E40 Fault - Causes & Fix

Yaskawa GA800 E40 Fault — What It Means

An E40 fault code does not appear in the verified Yaskawa GA800 service manuals or troubleshooting documentation. Yaskawa drives use specific alarm and fault numbering systems, and codes beginning with E may indicate a display-related alarm or an issue with an option card rather than a standard drive fault class. The exact meaning depends on your drive’s configuration, installed options, and firmware version.

Because E40 is not a manufacturer-documented code for the GA800 series, you must confirm the exact alphanumeric string shown on the operator display or keypad. Record your drive’s full model number, specification code, serial number, and any installed communication or I/O option cards before attempting diagnosis. Yaskawa technical support requires this information to identify non-standard codes.

Before You Replace Anything

Technicians sometimes replace the main control board when the real problem is a loose connector on an option card or a corrupted parameter setting. Before ordering parts, power down the drive, reseat all option cards and ribbon cables, then restore factory defaults and check if the code clears.

Jump to Fix

Common Causes

Unrecognized or custom alarm code The E40 designation may be generated by a communication card, external PLC, or custom parameter configuration not covered in standard GA800 documentation.
Loose or failed option card Communication modules, encoder feedback cards, or I/O expansion boards can trigger non-standard alarms if seated improperly or damaged.
Control board hardware fault A failing main control board may display garbled or undocumented codes, especially after power surges or overheating.
Parameter corruption or incompatible firmware Drive parameters can become corrupted during power loss or after a firmware update that does not match your hardware revision.
Wiring error in external control circuit Miswired start/stop signals, speed references, or interlock circuits can cause the drive to report alarms that do not match standard fault lists.
Cooling fan failure or control power supply issue Loss of cooling or low control voltage can produce atypical fault codes as the drive attempts to protect itself before shutdown.

Quick Diagnosis

Answer these to narrow it down fast.

Does the drive display change when you power-cycle it, or does E40 reappear immediately?

Yes: The fault is latched or stored in memory. Write down the exact code and any secondary information on the display, then attempt a parameter reset to factory defaults. If E40 persists after reset, the issue is hardware-related.
No: The fault may be intermittent or triggered by a specific operating condition. Monitor the drive during startup and under load, and note when E40 appears. Check all external control wiring and interlock circuits for loose connections.

Are there any option cards or communication modules installed in the drive?

Yes: Power down and remove each option card one at a time, then restart the drive. If E40 clears after removing a specific card, that card is either failed, incompatible, or improperly configured. Reseat the card and verify parameter settings for that option.
No: The issue is most likely in the main control board, wiring, or parameter configuration. Proceed to inspect all wiring terminals and control power supply voltages before contacting Yaskawa support with your drive model and serial number.

Does the drive run normally and only show E40 as a warning, or does it refuse to start?

Yes: E40 may be a non-critical alarm or advisory message. Consult the elementary wiring diagram for your system to identify which external device or signal is triggering the alarm. The drive may run with the alarm present if it is not a trip-level fault.
No: The drive is in a fault lockout state. This indicates a more serious hardware or configuration problem. Do not attempt to force a start. Verify control power supply voltage, check for damaged components on the control board, and prepare to contact Yaskawa technical support.

Step-by-Step Fix

Power down the drive and lock out all incoming power at the disconnect switch. Wait at least five minutes for DC bus capacitors to discharge before opening the drive enclosure.
Write down the exact fault code as it appears on the operator display or keypad, including any additional digits, letters, or secondary messages. Photograph the display if possible.
Record your drive nameplate information including the full model number, specification code, serial number, and any installed option cards or communication modules. Yaskawa support requires this data to identify non-standard codes.
Inspect all wiring connections at the drive terminals, paying special attention to control power (R, S, T for AC input and +24V, 0V for DC control), start/stop signals, speed reference inputs, and any interlock or enable circuits. Tighten any loose terminals.
Remove and reseat all option cards including communication modules, encoder feedback cards, and I/O expansion boards. Check for bent pins, corrosion, or damage to the card edge connectors and the backplane sockets.
Restore power and attempt a parameter reset to factory defaults using the keypad (consult your operator manual for the reset procedure, typically under initialization or parameter group). Observe whether E40 clears after reset.
Contact Yaskawa technical support with your fault code, drive identification data, and the results of the checks above. Request clarification of the E40 code for your specific drive model and configuration. Yaskawa may provide a software tool or parameter file to resolve the issue, or advise replacement of a specific component.
If instructed to replace the control board, transfer all option cards and parameter settings to the new board, then test the drive under no-load conditions before reconnecting the motor. Verify that E40 does not reappear and that all functions operate normally.

Parts Often Needed

Part	Notes
GA800 Control Board Assembly	Amazon \| Only replace after confirming with Yaskawa that E40 indicates a control board fault. Order using your drive’s full model and serial number to make sure correct revision.
Cooling Fan for GA800	Amazon \| Fan failure can cause thermal shutdown and atypical fault codes. Check for mechanical noise or stopped rotation before ordering.

When to Call a Pro

Call a qualified Yaskawa-authorized technician or contact Yaskawa technical support directly if E40 persists after you have verified all wiring, reseated option cards, and restored factory parameters. Non-standard fault codes often require access to proprietary diagnostic software, detailed knowledge of your system’s elementary diagram, and the ability to safely measure high-voltage DC bus and control circuit voltages. Because the GA800 can be configured with many optional communication protocols and I/O expansions, troubleshooting an undocumented code without manufacturer guidance risks damaging the drive or connected equipment. Professional support is also necessary if you suspect the main control board has failed, as replacement requires careful handling of static-sensitive components and transfer of configuration data.

Rough cost: A pro service call runs about $200–500 depending on whether the issue is wiring, an option card, or the control board.