About a year ago when driving on a 3ish hour trip, I made it almost to my destination and the hybrid warning lights came on. I noticed my windshield wipers were moving extremely slowly, and about five minutes later the screen and all the lights flickered off, the power steering went out, and I came to a dead stop on the side of the road. After calling a friend to come rescue me, they arrived and for fun I attempted to start my car and it ran fine, and the next time I drove it all the lights were off. I drove it for several months afterwards with no problem. It happened again a few months later and I took it to the dealer who "completely disassembled" my car and said they found nothing wrong with it. In the past two months it has happened four times, and each time if I calmly pull off the road, turn off the car, and let it sit for about ten minutes it will start right back up and drive perfectly. The obvious problem is I can't always pull off the road easily and so far have gotten pretty lucky in that aspect. Also, it's time consuming, annoying, and obviously not normal. I do a lot of highway driving, going back and forth between going to and from grad school as well as visiting friends in other cities. From what I've noticed, it doesn't fail on me driving on the highway, instead it runs fine on the highway but within about 10-15 minutes of city driving after getting off the highway is when it fails. Only once has it died in the middle of a highway drive, and once was after a long fairly steep uphill climb. It seems as if the battery bank is discharging as I drive down the highway and not regenerating anything with braking, and when it is used more in city driving it is unable to keep up with the demand? Any thoughts or suggestions? I'm trying to make this car last two more years until I get out of grad school and can afford a newer generation (I LOVE my prius besides this problem), and I'm hesitant to take it to the dealer again to have them take it apart, tell me nothings wrong, and charge me a bunch of money.
1) Have you checked the status of your 12 V battery (not the problem but always a good place to start) 2) These are classic symptoms of a failed inverter coolant pump. Since the pump is not working, the inverter overheats, when it shuts down, the inverter cools down and it runs fine. The way to check this is, turn your car to IG ON, open the hood and unscrew the cap off the inverter coolant reservoir. You should see flow or turbulence. If not, your inverter coolant pump is bad (which I already know it is). Report the results here please to confirm my diagnosis. The reason it only happens in town (or mostly) is that the airflow of hwy driving is enough to cool the inverter. The city driving limits this airflow. You need to get this repaired ASAP to avoid permanent damage to the inverter.
I would only add the Prius has half a dozen control computers that record error codes when there is a problem. But you'll need a Prius-aware, OBD scanner. Sharing the codes gives us a chance to share what Volume 1 of the manual set tells us the codes mean. Read the sticky and look at your own skills and tool set to understand how to succeed with this older car. GOOD LUCK! Bob Wilson
