2012 Prius starts, but not immediately...

Hi all,

My husband passed away in October. He was the original owner of his 2012 Prius, which currently has about 80K miles. I rarely drove it and do not know much about it, so please forgive me if the answer to my questions are obvious. I looked through this forum and it doesn't seem like anyone has posted this exact situation.

His Prius was not driven for about 3 months after he passed away. My Lexus recently needed a large repair and I needed a car to drive. I had some help jumping the Prius, and brought it in to Toyota for an oil change and a complete inspection. I asked for the 12v battery to be checked as well. Toyota told me everything looked good, and all I needed was an oil change. My car is fixed now, but I have enjoyed the Prius' fuel economy and I have been driving it almost daily.

Occasionally, it won't immediately start. It's usually after I shut off the car to run a quick errand, ike dropping my kids off at school or getting gas. So it's shut off for probably 5 or 10 minutes at the most. When I depress the gas pedal, the check engine light illuminates and flickers, and it seems like the car is trying to start. I usually wait about a minute or two and then re-try, and it will start fine. The "READY" sign does appear, and the dash looks normal after it starts. The key fob also does not work when the car is unable to start, and I also cannot lock or unlock it from the inside. But everything works fine after the car has started. I find this pretty perplexing, because it generally does start first thing in the morning, after it has not been driven for 12-15 hours.

Is there an issue with the 12v battery? The key fob? I suspect that Toyota maybe forgot to test the battery. I do not recall my husband ever replacing it, but I could be wrong.