Connected and powered 2.5 ECU.
LED #1 → ERR - indicates an ECU error and normally must be off.
LED #2 → MCU - indicates a response from the MCU - should be blinking.
LED #3 → 3V3 - indicates 3V3 supply line status.
LED #4 → 5V - indicates 5V supply line status.
LED #5 → 12V - indicates 12V supply line status.
LED #6 → 48V - indicated 48V supply line status.
ECU compartment lid removal