The tool is available in Android Auto 7.5.121104 – if you don’t currently have that version, you may wish to check for available updates. Rahman observed in a Twitter direct message that if the option is enabled, it may be found under Android Auto’s settings > Connection help > USB starting diagnostics. It’s worth mentioning that Google occasionally rolls out things in stages, so if you don’t see the diagnostic tool right away, you may simply have to wait for it to become accessible.
