LED states¶

Most rusEFI units have four status LEDs.

Blue: Communication
Red: Fatal/Critical error
Green: Engine status on many boards
Orange: misc

Some simpler units have only blue and red.

Bootloader¶

During the bootloader part of the power-on sequence, all four LEDs are expected to blink just to confirm life.

Normal operation¶

During normal operation, the blue LED is supposed to always blink at 50% duty cycle. The blue LED blinking frequency changes when USB connection is detected. Lack of any blinking means a brand new from factory unit or a completely unexpected firmware condition.

The green LED on many rusEFI boards indicates the engine status.

Off: Engine stopped
Blinking: Engine cranking
On: Engine running

Fatal error¶

Solid red means critical error; no engine operation is possible and a power cycle is required.