Total power loss when driving up a steep hill

Traction control. In many cars, it can be momentarily turned off with a button on the dash but not on the Gen2.

 

i think there is a way to turn it off in maintenance mode, but i don't know how. there maybe threads here, or video's on line.

 

Did the wheels slip on the rocks and wet leaves? If so, that is what tripped the Traction Control.

Older Prius vintages have more problems with this slippage-induced TC shutdown, newer designs handle it better.

 

What about a clogged catalytic converter?

 

Well like just about every other poster your hybrid battery is probably getting worn out. You never mentioned miles. If your at 175000+ start thinking about the hybrid battery.

The traction control just limits the instantaneous propulsion it should not basically shut the forwArd motion of the car off. It stops the wheel slip and then you can continue. At least that has been my experience. What your seeing is a power failure and I would imagine it has thrown a Christmas tree of lights on the dash the red master caution alarm at the least and if you see an icon of a car in the upper left corner of the mfd that’s hybrid battery death. That’s called the turtle.

Although you can shut traction off by putting the car in inspection mode but it should not be driven like that as you can over rev mg2.

 

When the traction control turns on, lights come on the dash blinking to let you know the traction control has enabled.

You can make wheel spin and therefore become "stuck" in almost any car. But you can also feather the throttle and make it move even on most of the extreme slopes in the mountains.

 

If you're flooring it up a steep hill, you're doing it wrong. Yes that will make wheel spin. When the wheels spin, the Prius disables all power to the wheels for a short time. Meaning if you floor it, you will come to a stop.

If you drive within the traction of the vehicle, no problem. Mine with more aggressive traction control (2006) makes it up extremely steep icy windy roads all the time. But I know how to drive. If the wheels spin, you've done something wrong.

 

But do they slip?

TC won't let them spin in the way cars did in the old days. But TC does flash a dashboard light.

 

Ok your not flooring it and invoking traction control its just running out of steam trying to get up a hill. The car should be very unhappy with that poor of performance and throw lights on the dash and log a code unless its strictly mechanical and out of the monitoring loop.
The person who suggested a clogged cat may be on to something there. Thats been posted a few times on this site. It kills engine power.

So it has no dash lights? No check engine lights?

 

It could also possibly be a (fairly uncommon) problem with the VVTi Control Valve or clogged VVTi filter. But I would be leaning more toward a HV battery at the lower end of the capacity spectrum.

When the OP says the HV battery was replaced, with what was it replaced? A Toyota new or a 3rd party rebuild/remanufactured HV battery?

 

The gas engine (ICE) is actually fairly low power compared to a traditional car since it relies on the electrical side to help out.

This is simple to troubleshoot: go back to the same location when it's dry and try again.

Finally, this may also be sign of poor tires.

 

A way to tell if you have a really bad traction battery is to floor it from a stop on a back road and watch the MFD. If the SOC goes down really quickly or you feel like the instant electric loses power you have an issue with the traction battery. If after the gas engine kicks in it seriously bogs down you probably have an issue with the catalog converter. But if the engine sounds like it is about to blow up it should be working fine. So you’re sure the car is not losing traction because of bad tires or leaves? Do you see the slip indicator flashing? It is a square light below the ready light.

 

Shortly after we got our 2006 we visited some friends at the end of a hilly dirt/gravel road. It was dicey most of the way, and almost impossible on the last climb up to their garage. It took several backups and a running start to keep power to the wheels. The wheels broke loose, traction light came on, and the power dropped to nil. When we finally arrived, they had 2 AWD Subaru in the garage. 2006 Prius had real problems on that road.

The 2006 drops power when one wheel spins, let alone two. Seems to me like applying the brake to the spinning wheel would help, but that's not how Toyota designed it. There's a reason Subaru sells well in ice/gravel territory. Plus a few extra inches of clearance. Keep a Prius on paved roads where it's designed to work...