With the new consumer financial protections that are going into effect very soon, PNC Bank will no longer offer overdraft coverage by default on checking accounts. You'll need to opt-in if you want any sort of overdraft coverage.
In researching the options, I found that PNC offers two forms of overdraft "solutions" that you can opt into. (The information on these is found here on the PNC site.) One of the options seems much more consumer-friendly than the other, and it seems like PNC is making it difficult to find information about and opt into it.
Option 1: Overdraft Coverage
The first option PNC offers, and the one they seem to really want you to use, is called "Overdraft Coverage". This is the coverage that we're used to from before the consumer protections: if you overdraft, the bank charges you a high fee (around $35) and gives you a short-term loan that covers the amount of the overdraft.
There's a lot of information on their site (linked above) about this option, and it's easy to opt into it from the online banking interface.
Option 2: Overdraft Protection
The second, more consumer-friendly solution is called "Overdraft Protection". With this option, when you overdraft your checking account, PNC will deduct the overdraft from your savings account. The fee for this is $10 per overdraft - less than 1/3 the fee for "overdraft coverage". (Presumably this is because the bank isn't technically loaning you money. They're just charging you $10 for the benefit of using your own money.)
At the time of writing, there's not much information on the PNC site about this option. PNC mentions that it exists and provides a basic summary, but there is no in-depth information online. You're told to contact customer service for information or to opt-in. You can't opt into this protection from the online banking site, either.
It seems clear to me that PNC would like you to enroll in "overdraft coverage" - they have much more information about this option on their site, and you can get information and opt into it using their online banking interface. It's obvious why this might be - the bank makes more than 3 times the money if you overdraft using this coverage rather than "overdraft protection".
If you're looking for some form of overdraft solution, I'd recommend asking customer service for information about "overdraft protection" - it seems much more consumer-friendly.