"ensures you" is correct and usable in written English.
You can use it when you want to express a guarantee or assurance of something. For example: Our guarantee ensures you satisfaction with your purchase.
But the novelist ensures you hear plenty in their silence.
This ensures you keep a top-quality copy of your work.
Buy at a price that ensures you won't be hurt too badly if you are wrong.
A night here ensures you get first tracks the following morning.
The challenge now is to implement a system that ensures you are rewarded fairly for what you do.
Technology ensures you never have to lose touch with friends and family if you don't want to.
Creating your own products ensures you have almost complete control over the ingredient and the manufacturing and packaging process.
Lib Dem children may appreciate the GLA's shower timer more: it ensures you stay in for just four minutes.
Not horrible, terminal cancer, but the kind that ensures you will never feel safe and complacent again, the kind that makes you rethink all you've ever known.
Buying from a dealer ensures you get the maximum legal protection since the law demands that the car is of satisfactory quality and fit for its purpose.
A built-in GPS ensures you never get lost.
