Is my transmission going? READ

If your transaxle had failed, then the driveability symptoms would be constant. The symptoms would not come and go. A new transaxle installed by your Toyota dealer would probably cost ~$6K.

If your car has a problem, and I think it is too soon to say that it does (given no warning lights), my guess is that the traction battery is the problem, given the excess engine revving that you noted. Maybe the battery ECU thinks the traction battery SOC is quite low, which causes the hybrid vehicle ECU to force the engine to rev so that MG1 will spin up and charge the battery. A new battery installed by your dealer will probably cost ~$3K, but if your car was first sold and originally licensed in CA then the battery should be warranted for 10 yr/150K miles.

 

I agree completely with Patrick. A traction battery issue is the main suspect, but as he says, it's too early to say for sure it's a real problem.

Tom

 

Do you have EV button installed by any chance?

 

The service manual includes some Problem Symptoms charts to follow when you have a problem but no code is recorded. I'd say it sounds like Hesitation/Poor acceleration and/or Surging. The chart says to check the fuel pump control circuit (make sure fuel is getting to the engine), injectors (ditto) and spark plugs (make sure it ignites) before checking the transaxle.

I'd tentatively add the torque damper/limiter to that list - if it's slipping, the engine power won't all be getting to the transaxle.

P3190, Poor Engine Power, is detected when the engine torque is less than 20% of the target torque, the engine has to be running faster than 750rpm, and it has to last longer than 100 revolutions or 6 seconds (these numbers do vary with engine temperature). So there could be a problem that the ECM isn't reporting because it's below the thresholds.

 

When I read the original post it seemed like the sensor for the gas pedal had extra hysteresis. I am not an expert at all though.

 

Before you went up the massive hill, did you come down that same hill? One of the probable causes could be an overly hot battery. If the battery is too hot, the Prius will try to avoid discharging/recharging it too much to keep the temp down, and you'll be stuck with mostly using the ICE for propulsion.

I've had this happen to me a few times. I'll drive down a big hill, regen braking all the way, and then park, almost right away, when I hit the bottom. This doesn't give the battery time to cool, as the battery fan shuts off when the car shuts off. When I get back in the car again, I will have shitty acceleration. I checked my CAN-View one time, and i think the battery was at a roasting 60c.

 

I have had this happen a few times with no hills... kind weird sent you a PM

 

Overheated battery would make sense... or an overheated inverter?

 

Hi All,

Does sound like a heat situation in the battery. Since the car was just started, inverter should not be too hot yet. What makes sense is you were still in stage one when you tried to go up the hill. In stage one, the car idles the engine mostly, and uses primarily the battery/motor for torque. If the battery is being protected because it was hot - no power. So, was this car parked out in the sun on a especially not day?

If so , you may want to get some Reflectix IR heat reflecting stuff and make a cover for your rear window, and crack the side windows. Even I do this here in Chicagoland.

But, its not unheard of for the battery fan and vents to get blocked. Small rodents are the most likely cause. Do you park the car by a wooded area ?

And its not unheard off to find a squirel's food reserves on top of the engine air-cleaner, or blocking the intake air passages. There is a resonator on the intake air plumbing, which would make a nice rodent nest.

The age of the car also indicates its time for a throttle mechanism cleaning. The small motor that opens the engine throttle can get overwhelmed with deposits in the bearings that support the butterfly. The reving incident seems to indicate that is happening.

 

To avoid overheating the battery system: *Do* use the A/C because it helps cool the battery system. Do not cover the battery cooling vent.

If you're unlucky this may be a symptom of a failing inverter coolant pump. If so there will soon be warning lights on the dash, guesswork will not be required.