LOUT
Briggs & Stratton Low Utility Voltage Sensing Fault

Controller displays LOUT or LOW UTILITY and generator starts even though utility power seems present.

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

Incorrect utility sense wiring at transfer switch, Loose neutral or sense conductor, Failed voltage sensing circuit on ATS board, Controller calibration error

How to Fix / Troubleshooting

Safety first: Turn OFF the utility main breaker and lock out if possible. Only qualified electricians should work inside the transfer switch.

  • Verify utility voltage: With a meter, confirm correct voltage at the utility lugs in the transfer switch. If voltage is normal, the issue is with sensing.
  • Check sense wiring: Identify the utility sense leads from the ATS to the generator controller. Ensure they are landed on the correct phases and neutral per the Briggs & Stratton wiring diagram.
  • Inspect ATS control board: Look for burned components or discoloration on the ATS control board. If present, replace the board with the correct Briggs & Stratton part.
  • Controller settings: Confirm that the utility low-voltage threshold is set correctly in the controller menu (if adjustable). Restore factory defaults if unsure.
  • Clear the code: After corrections, restore utility power, set controller to AUTO, and verify that the generator does not start when utility is normal.
Advertisements

Repair Difficulty

Hard 4/5

Required Part

Transfer Switch Control Board
Check Price on Amazon

We may earn a commission from links on this page.

Advertisements