START!
17 months is not too young. Matter of fact, there are MANY people, including myself, who practice 'Elimination Communication' (EC) with our children. Children are born with the knowledge of when they are peeing and pooping AND the instinct to NOT soil themselves. We teach them to go potty in their diaper and then expect them to re-learn something else later!
There is a great book, 'The Diaper Free Baby'. Of course much of it is dedicated to families who start EC early (I started when my daughter was 5 months old, many start at birth). BUT, it does have great information you can use for potty training.
But, here are the basics.
You need to get that body recognition back. As you pointed out, she doesn't know when she is peeing. So, it might be a little messy for a day or so.... but take it off. Take it ALL off. Put her in a t-shirt or something and let that butt go free. Pay attention to when she pees.... does she have to pee when she wakes up from a nap/bed? How long after she has a drink does she need to pee. Does she pee more in the morning, afternoon?
Timing is your friend. If you can get her on the potty when you anticipate she needs to pee...then do so. Make it a big deal. Have a potty party with her. Sing songs, clap...whatever to make it fun. Whether you catch a pee in the potty, or if she goes on the floor... TELL HER what she is doing. Say 'You're going pee!' Not angrily ... but excitedly. She WILL get the connection. It won't take long before she connects the words 'you're going pee' with the sensation of actually going pee.
As far as pooping. I'm sure she has gotten into a rythmn for that. So, put her on the potty just before you think she has to poop. OR, if you see 'the look' .... get her on the potty.
Kids are really smart and we don't give them enough credit. She will get this. Noone wants to sit in their own waste. It's yucky.
I can't believe how many moms I hear say 'I know when my kid is going poop... he/she gets this glazed look and I just know what is happening' Yet... they sit and WATCH and let them go in their diaper! WHY!? Would YOU want to sit in your own poop??? If you know it is happening ... why not just put them on the potty!?
Baby Bjorn has a great little potty chair. Perfect size. They also have a bigger one that is more expensive. But the simple little potty chair is typically about $10 or something. It's all one piece and comes in lots of colors. Amazon sells it, I think Target also sells it. If you don't have a potty chair yet that is.
Have Fun! I would say definitely start getting that diaper off!
Oh... and for those who think this is nuts. My daughter goes poop in the potty, we catch many of her pees through the day, she WILL tell me through sign language when she has to go, and another friend of mine ... her daughter was completely out of diapers by the age of 15 months. There was no struggle, no coercion, just good ole communication with our children on meeting their elimination needs.