Stall and slowness problem 2017 Prius

It's surprising that you are not seeing any warning lights. When you saw the message saying the hybrid system was disengaged, did it appear only briefly or remain until you restarted the car? I would certainly think that would register a code. Did the dealer tell you they had not found any codes? I wonder how thoroughly they tried to diagnose the problem. It definitely sounds like there is some type of problem with the battery driven part of the propulsion system.

 

Sounds like the IPM malfunction in Gen 3 series. Perhaps review those threads...

 

i thought there was a tsb, could be misremembering. did the engine rev at all when you stepped on the gas?

 

Maybe having a passenger take a good quality video would be helpful.

Above all, be SURE that you have this documented with your dealer......and that you get a paper copy.....just incase it continues to be intermittent until AFTER the warranty expires.

 

Here is the info from one thread in Gen 3, Prius went into limp mode on freeway, IPM failure | PriusChat

 

i wonder if it is a traction control issue. still, you'd expect a dash light.

 

night time would probably eliminate battery overheating issues.

 

There must have been codes set, considering you saw a warning, and there was a definite change in the car's behaviour. They're dragging their feet??

 

That's a warning I think.

 

Which trim level is your 2017 Prius? If it’s a Prius One or Prius Two, with the NiMH battery, the problem you describe might be corrected by the firmware update described in T-SB-0241-17, “Reduced Power When Accelerating From a Stop.” See this thread:

TSB (NiMH only): Reduced power when accelerating from a stop | PriusChat

It’s been discussed before:

Intermittently Doesn't Start from Stop | PriusChat
2016 Prius wont accelerate when stopped | PriusChat

If that bulletin doesn’t apply to your car, or the update doesn’t fix the problem, I’d also suggest making sure the dealer has checked for Vehicle Control History events. See post #9 in this thread:

A couple of things I have noticed | PriusChat

Also, do you recall the exact text of the message that appeared on the display? Was it “Hybrid System Stopped Shift to P” or “Hybrid System Stopped Stop in a Safe Place,” for example?

 

I'm having the a similar problem with my 2017 Prius Two. It's been to the dealership 3 times and I contacted corporate, but they haven't been able to find an issue with the vehicle and are kicking it back to me at this point. I have little more than 12K miles on the vehicle at this point and it's "stalled out" 3 times in the last 35 days. No error codes, but it does show that the MPG took a steep dive one day it happened (July 27th.) Car left me hanging out in the middle of an intersection when it started acting up the first time. :-/

 

YOu should not take this without a fight.

Given the potential safety implications, I think you should report this to the NTSB/NHTSA and start looking into the lemon laws in your state.
Most places, if they can't fix it after 3 tries, they owe you a new car.

 

Contact corporate Toyota. Present them everything that's happened so far.