Slipping transmission

i don't think you are describing the symptoms correctly. can you provide more detail?

if there were a tranny or battery problem, you would have trouble lights.

how many miles on her?

 

Even in conventional transmissions, decelerating would be a pretty weird time for a transmission to slip.

And in a Prius transmission, there is nearly nothing that even can slip.

Can you take a step back and describe exactly what you notice the car doing, at the times when you describe it as "slipping"?

 

If you are slowing down using regenerative braking and a wheel loses traction due to a bump or gravel, the computer will shut down regenerative baking for a very short time. You could perceive the change in deceleration as a slippage or even (as some have in the past) an instance of "sudden acceleration.

JeffD

 

?

 

Start by cleaning the battery cooling fan and its ductwork under the left rear seat.

If the battery can't cool itself properly, the car will drive weird. The battery breathes cabin air, so the cooler you keep yourself, the cooler the battery is.

Eventually the battery wears out and then the car drives even weirder.

 

how many miles on her?

how many years and miles have you owned her?

has she had all regular maintenance?

are there any strange sounds you can record?

any trouble lights on?

when did the misbehavior begin?

unfortunately, nothing in your description is helpful for internet diagnosis

 

Maybe we need to begin by asking what are this car's pronouns?

 

Never anthropomorphize your car. They hate when you do that.

 

cars are female, there's no getting around it

 

Normal to have high revs when decelerating

 

Late response, but this is a symptom of a "tired" battery. There's something the hybrid system doesn't like, so it's going into a sort of battery preservation mode, where it will neither charge nor discharge the battery. Like Leadfoot said, it could be as simple as overheat, where the battery fan duct has a plastic bag obstructing it.

Chances are, if you look at a scan tool, you'll see a pending P0A80 code. This is a two trip code, so it has to happen twice within a set time to become a permanent code and turn the money light on. The good news is that if this is the case, it sometimes will go another couple of years before giving up.

Also with a good scan tool, you can look at the freeze frame data for the pending code. It'll show the highest and lowest battery block voltages. A 1.2V difference will set this code.

 

I think in this thread we've been gynomorphizing them.

 

That description does seem to be a little more precise.