Yaskawa GA500 AC Drive
Yaskawa GA500 AC Drive code EF: FWD/REV Run Command Input Error
Forward and reverse commands were input simultaneously for over half a second, causing the drive to stop operating.
- Code
- EF
- Name
- FWD/REV Run Command Input Error
- Controller
- Yaskawa GA500 AC Drive
- Type
- Safety interlock
- What it does
- Warning: the equipment keeps running and flags a problem
- Risk
- GREEN In your wheelhouse
- Reset
- Clears on its own when the condition goes away
- Source
- The manufacturer's manual (subscribers see which manual and page)
Updated November 4, 2026
How to fix it
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- What to do next, in plain words
- What the manual says to do, and the page it is on
- The 1 common cause listed for this code
- The step by step check for this problem, one check at a time
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Questions about this code
What does Yaskawa GA500 AC Drive code EF mean?
Forward and reverse commands were input simultaneously for over half a second, causing the drive to stop operating.
Is Yaskawa GA500 AC Drive code EF dangerous?
It is graded green: in a working tech's wheelhouse with standard tools and low risk.
How do I fix Yaskawa GA500 AC Drive code EF?
The manual's fix and the step by step check for this code are in WERCS Diagnose, plans from $49 a month. For help right now, WERCS answers 24/7 at (877) 489-3727.