Transmission slip??? Dangerous problem I'm having

It could be traction control kicking in. Does it only happen when turning? Bad wheel sensors can create havoc , but usually throw codes. Could yours be flacky only when turning?

Its not the transmission. Your car has gears, but no transmission.

 

You could be having the same issue as Wes and I are having. Sounds pretty similar...
Stall and slowness problem 2017 Prius | PriusChat

 

It's because they're "technicians", not "mechanics."

 

Was there any resolution to this? I have a 2018 and it's doing the same thing. Only on hot days so far.

 

It might be better to start a new thread, and describe the exact behavior of your car as precisely as you can. This thread is a year old, and the original poster never really added enough detail to support saying whether another person's car "is doing the same thing" or not.

The transmission in the Prius doesn't have parts prone to "slip". But it is designed to take advantage of a boost from the traction battery to improve acceleration, so when that power isn't forthcoming from the battery, acceleration will be less and the engine will rev higher to compensate, which is a lot like what "slip" feels like in a conventional car, so people will describe that sometimes.

If it happens on isolated occasions when the battery charge has been depleted or the battery temperature triggers power limiting (such as a long hard pull up a steep hill, or slow but hilly drive in high temps) it is normal and no sign of a problem. If it starts happening in situations where it never did before, that can be worth a look.

High temperature in the electronics can also lead to a power limitation, with a similar feel.

 

Have all Inverter/IMG TSBs been accomplished?

 

I took it to the dealer and said there were no codes or TSBs. ChapmanF's post is exactly what is going on with mine. It was a very hot day and the hybrid battery had 2 bars at the time. His description describes what mine is doing, so hopefully it's just an isolated incident.

 

People are sissy and complaint about anything although that's how e-CVT works and last forever.

 

Battery is very simple to replace, new battery should be in the $160 range if prodded or pushed, I got one from dealer for $165 by complaining about cost ($195) and threatening to go to Interstate Battery for one of theirs for $156.

 

The knob on the end of the shifter is also very simple to replace, and only $60.54.

 

A. I know this is an OLD thread - but wanted to make a point.

B. I also know(?) that the OP meant the above statement as a snarky comeback to a less-than-helpful service writer or technician - but that it's actually a pretty sound suggestion.

Back in the olden days as a mechanic at a Buick dealership - it was pretty common for a customer to bring in a car with a complaint ("makes a noise when I _____", "stalls out when you _____", etc) and invariably - during the 5-minute "test drive" - there's no noise, the engine runs fine, the transmission shifts perfectly, etc. IOW - when the mechanic is there, the car is on it's best behaviour. (This is how machines make their operators look like idiots BTW)

The solution we offered our customer in this case is that we'll give you a loaner - and take you car for a day or two and drive it around - back and forth home to work, etc. That gives the service writer or mechanic a much better opportunity to diagnose the car and hopefully re-create the problem. The problem is much more likely to be detectable when the car gets driven for more than a mile.

Anyway - that's how we used to do it back in the 20th century......

 

That's one killer video on the Prius Transaxle!

Just started it but looks like I'll learn way more than I really want to.

The guy is a bit of a slow talker, so I found that running it at 1.25 playback speed doesn't drone me off to sleep.

 

Are people really doing that???

 

Adds 20 RWHP… with the decals, 10 more.

 

I've seen it done.

 

Wow...

Very cool.

I'm actually surprised that for as complicated as this transaxle is - it's pretty darn simple.

I think I'd tackle one of these before I'd dig into an old GM "Hydromatic" transmission with all the band and hydraulics.

What's also cool is how the "CVT" function works. I was expecting something much more complicated.

 

I am having that exact problem with a friend aqua. It is exactly like a transmission judder in low gear with the transition from ev to ice you can replicate it over and over by switching to ev and it goes away. When the engine kicks in at low speeds foot barely on the gas it sounds like the tranny is going to fall apart. I narrowed it down maybe to the transaxle system maybe the motor/generator or the gear set units, also there is senso called a resolver that senses the exact position/polarity of the motors can maybe is defective. But I will get in contact with my hybrid instructor for advice. There is absolutely no codes and I did disconnect the aux battery. Nada, will keep you updated.

 

That sounds exactly, totally, different from everything this thread is about, which was a "slip" feeling as described in the title, not a judder.

Responses will probably be less muddled if you start a thread for your judder issue (if you haven't already).

 

You'd be better to start a new thread as ChapmanF suggested - in the PRIUS c FORUM - you'd be more likely to find people with that car, and maybe that issue than here. The cars are quite different.

 

I have 2 second gen priuses and I put $30 12v lawn tractor batteries in them and they work just fine. I have been doing this for over 10 years. You do have to modify the connectors but it is easy.