What does the etc arrears mean?

The prompt content of etc arrearage SMS: First of all, if etc is in arrears, he will send a short message saying that the Etc card you are currently using will be in arrears, so please recharge it in time. Then he said that if you read this letter, it will be recharged in time, otherwise your card will not be used normally when passing through the toll booth, so, um, in this case, I suggest you continue to draw such a message.