My 2005 prius just had a sudden power loss after 5 minutes of regular driving on a -4F (-20c) morning. The check engine light went on and the car seemed limited to 10mph. The battery symbol rapidly drained to 2 bars. This happened last winter once but when brought to the mechanic, they found nothing and the car worked normally afterwards til now. any advice welcome.
Since check engine light was on there are codes on memory. You should check them. Check engine codes can be read with normal obd2 reader. But to get all codes and more information you need Toyota hybrid capable scanner. If you want to do it yourself get techstream. Post codes here and probably somebody can help you.
Sounds to me like lack or restriction of fuel. It there any chance that the fuel line has frozen? (water in the fuel). I can't believe it would, but stranger things have happened.
Back on the farm, it used to happen like clockwork as soon as it got well below freezing. Ice would collect in the fuel line and restrict fuel flow. A few ounces of gas line antifreeze usually did the trick. It rarely happens nowadays; fuel tanks are better sealed, and the ethanol in most gasoline acts like gas line antifreeze.
