Yaskawa GA500 AC Drive
Yaskawa GA500 AC Drive code Er-04: Line-to-Line Resistance Error
Auto-tuning failed to measure the line-to-line resistance correctly, preventing the drive from operating the motor properly.
- Code
- Er-04
- Name
- Line-to-Line Resistance Error
- Controller
- Yaskawa GA500 AC Drive
- Type
- Setup or parameter fault
- What it does
- Fault: the equipment trips and stops
- Risk
- YELLOW Booth plays by its own rules
- Reset
- Needs a manual reset
- Source
- The manufacturer's manual (subscribers see which manual and page)
Updated November 4, 2026
How to fix it
Subscribers get:
- What to do next, in plain words
- What the manual says to do, and the page it is on
- The 4 common causes listed for this code
- Booking a live video call with Ben, a master booth technician ($250/hr, paid per call)
Questions about this code
What does Yaskawa GA500 AC Drive code Er-04 mean?
Auto-tuning failed to measure the line-to-line resistance correctly, preventing the drive from operating the motor properly.
Is Yaskawa GA500 AC Drive code Er-04 dangerous?
It is graded yellow: not hard, but a booth does it differently than the gear most techs know, so follow the checks in order.
How do I fix Yaskawa GA500 AC Drive code Er-04?
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.