Reving after releasing gas.

Thank you Matt for the tips. I haven't gotten around to fixing the problem but this makes things easier.

 

Hey I went ahead and cleaned the inlet and boy was it nasty. I hope that solves the problem. Now I have another problem. How do I reinsert those plastic button things. It seems like they won't fit anymore having expanded while taking them out. Thanks again.

 

Think I'm going to be forced to look into this. For the first time today, I heard that fan blasting at high speed while out and about. Freaked me out because I didn't know where the airy noise was emanating (I double and triple checked the window while driving). Checked the back, and there was no visible obstacle at the base of the floor. It's also a nonsmoking and no pets vehicle, but dust could be the culprit given I'm in the high desert.

 

I'm bumping this thread as I'm experiencing this issue, and nothing appears to be blocking the vent in the back seat that seems to have solved the problems for other folks. I've noticed that when driving to work in the morning on the freeway, if I accelerate then lift my foot off of the gas pedal, the engine will rev high for several seconds after my foot has left the pedal. My MPG has been pretty terrible lately as well. It's been really cold here, but this should not be causing this problem, right? I'm going to have to head back out to the dealer for the third major issue with this car since getting it brand new. It only has 8000 miles on it. Sigh.

At any rate, wanted to grouse and see if anyone else has had this issue with a source other than the blocked vent.

 

I have this issue every once in a while.. mine seems to happen after a quick run to the store/gas station. On the return trip, it will hold revs and the brakes feel weird. The last few times it's happened, I pressed the brake pedal down as far as I could while at a stop light just to see what happens, the car made its usual "whirring" sound like when you open the door first thing in the morning, then it seemed to drive properly after that. I'm wondering if it's something in the ECU, like it needs to relearn throttle/brake positions etc.

I have quite a few friends that work a toyota dealership, both service advisors and technicians, and they have no advice for me since there are no engine lights/codes etc. on paper, the car is technically "operating to manufacturer specifications".

edit: I have also cleaned the battery vent, mine wasn't dirty at all.

 

I rev a little after gassing.

 

Any update to this? Mine started to over rev everytime I drive now.

Just swapped out the Hybrid Battery with a brand new one, with a brand new blower. Vent isn't blocked, fan kicks on, if a/c is set to high, the blower spins really fast, where I can reach behind the drivers seat, hand on fan inlet, and feel the air moving.

Checked fuses, nothing blow.

 

Is the cabin hot, even with the AC on high? Does the revving slow down when the cabin cools off?

 

Happens if Cabin is cool. I even let the car warm up for 10 minutes before driving. I'll make more observations today to how full the battery is and if I ease off the gas slowly to see if it still happens.

I maybe paranoid, but I don't see the hybrid Battery get full. I usually have the 30 min MPG display on the small screen next to the speedometer, and the bigger display screen shows the same info, the MPG display chart. The right side of the screen is partially covered by my 'CD phone Mount', so I haven't seen the battery meter in over 2 years to be honest. I remember reading a while back that the car wont fully charge battery, and it will leave 2 bars empty.

 

My engine comes on to charge the battery when I am not stepping on the gas- also there are times that I step on the gas and the engine is not working (ev mode). When the engine revs seems to be a separate issue from when you hit the gas.

 

Several things happening here. One cause of the engine revving high when you step on the accelerator, is the battery temperature being high. In this case, if you watch the battery monitor, you'll see that it doesn't move much. The car is trying to use the ICE more, and put less stress on the battery. Less charging and discharging. The car is very smart about protecting itself.

The other situation, and one that seems to alarm people the most, is when there's nothing wrong, and you step off the accelerator, and the engine revs high. Problem here is that no one but Toyota really knows what the THS theory of operation is... The dealer is not Toyota, so they have no idea, either. Talking with other industry experts, I believe it's some kind of battery exercise, where the HV ECU goes into some kind of battery conditioning cycle. When it happens in my Toyota and Lexus hybrids, it's often when the battery goes low, but I've also seen where the battery is almost topped off, and then discharges very rapidly. Then the engine will stay at elevated RPM, and flare when the accelerator is released. The battery rapidly charges again. It may go through this cycle a few times, and then normal operation is restored.

I've talked to one person who I can't name, as he works for Toyota on hybrid programs... and he hinted at this, while not being able to directly tell me that this is what's happening. "TMG Proprietary Information."

The bottom line is that the car is a rolling electronic marvel. If there is something "wrong" with it, it will let you know in the form of a lit up dash ;-)

 

It will leave 2 bars empty unless you're descending a very steep hill. But even then, it'll get rid of it quickly.

 

Glad I worried about nothing about the battery never being full.

The engine seems to over rev when I lift off the the gas pedal to coast at highway speeds (55 MPH+) AND when the battery is 'full' meaning the top 2 bars empty.

This seems like the inverter making the noise since it seems comes from directly in front of the drivers seat and not so much from the ICE engine slightly towards passenger side. Could the inverter be having issues ? This has not happened before. Maybe I need to disconnect the 12V battery for a while and let it sit and then hook it up?
I'll order a OBD2 scanner make 100% sure it's not the engine reving higher.

Any suggestions for a OBD2 scanner that wont break the bank? Scanguage is a little pricey for me at the moment. Looking at something $50 or below.

 

I've noticed this first time today (after two month of owning 2013 C/2. Yesterday I was driving about 15 miles after gasoline indicator started blinking, and then got a full tank of regular gas. So, I was thinking that it could be a ECU trying to adjust to a new gasoline. However after reading this thread, I will check the battery vent (when rain stops).

 

Check the vent, but next question, was it hot? Like 90 degrees hot?

 

It was not that hot, but rainy... I think it was some shopping bags that could block the vent. Didn't have it since...

PS. And I checked the vent - looks like the dealer actually cleaned it before the car was sold, as it was squicky clean.

 

My 2012 was doing this for about a month before the traction battery failed.

I replaced the traction battery, disconnected the 12 volt battery for 2 minutes, and cleared the "fluff" off the vent fan. Hasn't happened since. (600 miles)

 

A blocked vent will act like that too. Most likely that was your issue.

 

Hey folks so had this issue for a while with my 2013 c. It was freaking me out.
Just popped the plastic things and found like a wad of hair and dirt.
Attached some photos.
Can't quite get the clips back in properly but here are some photos I uploaded.

Will post if it seems to have solved this issue . Twice tried toyota dealership... useless... absolutely useless...

Prius C Revving Battery | PriusChat

 

gross!