Raspberry Pi GPIO pins work at 3.3 V and are not 5 V tolerant. A 5 V signal can damage the board.
What the message means
The pins connect directly to the processor. They give only a few milliamps per pin, so they cannot drive motors or relays directly.
Fix it in this order
- Use a level shifter or a resistor divider for any 5 V output going into a GPIO.
- Drive motors, relays and large LEDs through a driver or transistor, not from the pin.
- Power sensors from the 3.3 V or 5 V pins as the sensor requires, and join the grounds.
- Check the pin numbering mode in your code: BCM numbers or physical board numbers.
- Disconnect power before changing wiring.
If you see this, do this
| You see | Do this |
|---|---|
| Pi restarts when a motor starts | Separate the motor supply and add a driver. |
| Pin reads wrong level | Check the numbering mode. |
Related
wiring checker, relay module active low.
Last reviewed: November 2026. These are the usual causes and the order that finds them fastest. Test on your own board; clones and cables differ.