Coolant...
It's a 2009 so I'm sure the coolant is o.k. but normally, you'd use a hydrometer to check and make sure it is still good to hold the motor during a freeze.
Your open loop system is all you need to protect. There are sticky threads in the PWC topic in winterizing the 4-TEC. I've heard from other owners that have the 09 models and they have said that BRP is now recommending that you just blow out the excess water. You can do this with a compressor or, you can start the engine and allow it to run for a minute with the hose disconnected. The engine's ride plate should not get to hot during this procedure.
You also need to make sure you spray all your linkages and your pump down with a protectant like WD-40...........:cheers: