Should I change my transmission fluid?

yes, hybrids don't have conventional transmissions where people believe that the small orifices and etc. that can get cleaned out during a fluid change will negatively affect the transmission.
although toyota calls it lifetime fluid, most here would recommend changing it.

 

Never too late, I would.

The engine and transaxle are similar to gen 2 Prius. Prius c Owner's Manual says (on page 502):



It may have distinct drain/fill bolt types, so good to have another vehicle available, in case you need to score an extra socket. At least for first time, I'd get the fluid and fill/drain bolt washers from the dealership, and note the washer part numbers.

There's a link in my signature*, specific to gen 3 transaxle fluid change. I don't have Prius c Repair Manual, but the technique is similar.

* on a phone turn it landscape to see signatures..

 

Yes service your transmission as stated...and flush your brake fluid too. DOT 3/4 is not lifetime either.

 

No, it's not too late to change it.

Yes, hybrids are different, especially the Prius. Normal transmissions pump the fluid through valve bodies that send the pressure to various bands and clutch packs that have friction material that clamps down on metal. This generates heat when it slips, and both the metal and the friction material end up in the transmission fluid. The prius uses an eCVT (which is different than the CVTs that uses the variable pullys). This has two electric motor/generators and planetary gears that have the gliding and gripping actions from a normal automatic transmission. There's no accumulation of friction material and metal that builds up in the transmission fluid, or the heat generating friction that breaks down the transmission fluid.

Don't substitute the fluid when you change it. Go to the Toyota dealer and pick up the fluid in the parts department. If you have it done, don't let them use anything else.

 

I'm thinking you meant to type "that don't have the gliding and gripping actions", right?