Speakers generally work when they are connected to the radio and not shorted out. You can test the terminals with a multimeter to see if its getting power.
In the Echo - 2002 TV was released on: USA: 2002
Be My Echo was created in 2002.
Echo - 2002 is rated/received certificates of: Belgium:KT
Galeria Echo was created in 2002.
the fuel filter is plugged
Forty Foot Echo was created in 2002.
Echo dot is smarter but google home mini has a better speaker.
For my 2002 Echo it is 3.7 Liters with a filter change.
Open your trunk and check the rear speaker wires - chances are something banged into them and damaged the wiring creating a short. If so, you can fix the wire or clip it (in which case you would lose sound in one rear speaker but your radio will work again).
The 2002 Toyota Echo OBD 2 port is under driver side dash next to kick panel
http://pdftown.com/2000-2002-Toyota-Echo-Service-Manual.html
Yes, you can use Alexa with any Bluetooth speaker without an Amazon Echo by using the Alexa app on your smartphone. Simply pair your Bluetooth speaker with your phone, then open the Alexa app to interact with Alexa through the speaker. However, keep in mind that you'll need to have the app open and your phone nearby for it to work.