My ELM327 is not connecting to the ECU, what should I do?

If you are having trouble connecting to the ECU first start by trying to connect to another vehicle. If the elm connects to that vehicle just fine there is a problem establishing a connection between the first vehicle and the ELM327.

If the ELM327 fails to connect to the new vehicle, reset your connections be it Bluetooth or Wifi and/or uninstall the USB driver if you are using a USB interface. After all drivers have been removed, proceed to go through the setup for your elm again and if needed, reinstall any drivers. From there attempt to connect to the vehicle again. If it doesn't work, you can try connecting to a third vehicle or contact the manufacturer and ask them if you can send the ELM327 back to them and have them check it or send a tested replacement.