Prius ICE overspeed problem

This sounds weird. I would definitely visit the dealer if I were you, especially if the warranty is about to expire. You wrote that the car did this since it was new; did you try to solve this problem earlier, and what were the results? Did you tell the dealer about it ever before?

 

This is a new one.

However your assumption that the car is still under warranty may not be warranted. The powertrain warranty is 5 yrs/60K miles (in the US.) There are so many warranties: powertrain, emissions, hybrid system - that it is hard to tell which warranty will be invoked.

Also, if no warning lights have appeared then no DTC have been logged. Unless you can replicate this problem on demand, it is questionable whether the Toyota dealer tech will do much for you.

Maybe you can ask your dealer whether there are any firmware updates that could be downloaded to your engine and hybrid vehicle ECUs.

 

what kind of device are you using to readout the info you got like rmp's?
the prius got no ice rpm indicator and so no redline
also the devices used to readout canbus data do not present you with a redline?

i guess a really cold battery pack ( so the ice wil be used more )

 

how many bars on the battery meter when this happens?

 

Until a solution found, how about accelerating at less than full throttle on a cold engine?

 

yes i think thats the case.
also the 5000 rpm redline is not really a redline thats problem
the prius ice wil never ( unless something is broke like a ecu and then i guess the car will shutdown instead of keep running or a big red warming light ) over revv

as you know from using the scanG the ice rpm and speed are not always related.

 

The OP states in the first post: "the ICE will overspeed (revs up well over 5,000 RPM)". This suggests something other than normal operation.

Tom

 

well over? like in 5200? 5300? sound stil normal to me
lets firts asks what the rpm is the the TS experienced.

 

Hi All,

It does take some current to MG1 to control the power transfer from the engine to the the wheels. If the battery power is so low (at -35 F!, -40F is -40C) it may require a warm up time to get to normal operation. At really cold temps, there might not be enough current capacity in the battery to result in the power transfer to the wheels, and thus the high ICE RPM. The traction battery does loose power at cold temps. I believe I read something like 10 hp at 0 F, instead of 30 hp at 77 F somewhere. At -35F its gotta be even worse. In the book on the history of the Prius the guys killed in the helicopter accident had just succeeded in getting good start/stop action of the engine at -20C. That maybe the lower temp spec for the car (without modification).

Sounds like a good work around would be to stay off the highway till the next ramp to avoid the problem at higher power levels until the battery gets warmed a little by charge/discharge action. A battery blanket might be in order at these temps. I believe they sell heater blankets for traditional car starter batteries to have normal operation in temps below -10 F.

 

If you've got a Scangauge try programming the Traction battery voltage and current codes into the unit. You could then check as to whether the voltage and current values are anywhere the normal levels to provide the necessary resistive torque to the ICE under heavy acceleration. The values required in the x-gauge codes are in the attached .xls spreadsheet.

 

how many bars on the battery meter when this happens?

 

Bonjour Francois:
I think that you may be able to fix this by changing the TPS adjustment. This is only a guess, since the symptoms are not exactly the same as I had, but the over revving is a common symptom. In my case, I needed to reduce the ICE off TPS setting from 14% to 9%. You should be able to read the TPS setting with your scan tool, and see where it is set. Try lowering it a few %, and see if the problem goes away or improves. The dealer was no help with this, had the car for 2 weeks, and couldn't figure it out.
Good luck!
Howard

P.S. The TPS is on the throttle body, on the right side under the air cleaner, and is held by 2 screws.

 

At low speeds and high engine RPM MG1 actually produces power as generator rather than consuming it. It would be charging the battery or sending the power to MG2.

At lwo road speeds the current limitations (100A) of MG2 (and power limitation of MG1) mean that then engine cannot normally be allowed to produce full power so it is limited to a lower RPM. It sounds as if the throttle actuator is not functioning properly (sticking?).

kevin