Self Diagnostics

Hi all,

I'm curious as to how much monitoring and diagnostics the Prius onboard computer systems perform, for both the engine and electrics. The reason I'm asking is that as a new Prius driver, I'm not allways sure whether all the noises are normal.

So, If there are no warnings, red/orange lights and klaxons, I can be assured that all is normal?

For example, let's say there is some firing problem with one of the spark plugs or an issue with the HSD. What will the computer tell me? Check engine light? Triangle of death.

How extensive is the systems' self checking?