Newbie to Prius Troubleshooting

welcome!

the battery has to be tested under load. you can either purchase tech stream software on line, and an old compatible laptop, or you can remove each module and load test with a light bulb.

there are many threads here describing both procedures. diagnosing and rebuilding a battery is painstaking, but cheap if you have the time. reliability is sketchy though.

try calling toyota and asking for goodwill warranty help on a new battery, you never know.

all the best!

 

You might want to take it for a quick test drive around the block to see if most of the power is back. What you describe happened to me when my hybrid system failed and the gas engine had to do all the work. The result was a gas engine that got too warm. This could be because of any number of high-voltage reasons. For me, my hybrid battery got too weak.

When the gas engine carries too much of the load, it stops charging the hybrid battery. If you have something like an air conditioner on, the high voltage battery will quickly deplete. When things get bad enough, the car will stop using the hybrid battery altogether, and all symbology to it on the display will stop. Your car will lose acceleration, and not have a very high top end speed. It may idle at 40 or 45 MPH, but you may not be able to go much faster. Flooring it will not do anything for you when you are in that state.

In my case if I cycled power most symptoms were gone until the engine was sensed as being too hot again.

If it is a problem with your high-voltage system, then the best thing you can do is limit your miles, start out and drive slow, stay off highways, and don't jump out into traffic. And don't use the air conditioner, because you want the high-voltage battery to retain some level of charge (if the system is still capable of recharging it).

Hopefully a test drive around the block will go well, as the gas engine should be cool now. If so, you should be able to get it somewhere where you can have your codes read. Or you can use your trailer. For me, I was able to drive to & from short distances (up to about 5 miles) with only a hesitation when starting out. So no matter what, because of the hesitation (and possible overheat condition) always leave plenty of room when pulling out into traffic. And get those codes read.

 

Welcome to Prius Chat .

Some questions:

• Are there any dash lights displayed?
• Do you have a way to read the codes?
• When your son bought the Prius, did it come with maintenance records?
• Had the inverter water pump ever been replaced?
• Hybrid battery fan been cleaned?
• Has your son ever heard the fan run?

As @bisco mentions above, Techstream is the software to use for troubleshooting .

I’d look into getting that software for diagnostics to help before a shot gun parts replacement approach or jumping in head first.

Good luck and keep us posted .