E20
Yamaha
Transfer Switch Communication Fault
Generator display shows E20 and the unit will not start in AUTO mode.
Advertisements
Safety Warning
This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.
If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.
Advertisements
Possible Causes
Open or shorted communication cable between generator and ATS, Incorrect wiring at ATS terminals, Faulty ATS controller, Failed generator controller communication port
How to Fix / Troubleshooting
Safety first: Ensure the transfer switch is in a safe position and that backfeed to the utility is impossible. Turn OFF the generator and disconnect battery negative.
- Inspect comm cable: Locate the low-voltage communication cable between the Yamaha generator controller and the automatic transfer switch (ATS). Check for physical damage and reseat connectors.
- Verify wiring: Compare wiring at the ATS and generator terminals to the Yamaha installation diagram. Correct any miswiring.
- Test continuity: Use a multimeter to check each conductor in the communication cable for continuity and absence of shorts.
- Check ATS controller: If possible, view ATS status LEDs or display for errors. Replace the ATS controller if it does not power up or communicate.
- Controller port test: If a known-good ATS and cable still do not communicate, the generator controller communication port may be defective and require replacement.
Advertisements
Repair Difficulty
Hard
4/5
Required Part
Automatic Transfer Switch Controller
Check Price on Amazon
We may earn a commission from links on this page.
Advertisements