Hi I have a Gen II 2008 with 109000k miles It seems when it gets hot here in Arizona (near 100 or >) that for a period of time driving home the car will not shift into the next gear properly. I have to back down on the accelerator to get it to shift to a higher gear or whatever the trans axle is not doing. There are no check engine lights or codes be thrown. Is there a sensor that could be causing this behavior or are there internal clutches slipping Oddly later driving home things seemed back to normal. Greg
There are no internal clutches, or "gears" for that matter. Maybe the hybrid vehicle ECU is overheating in the hot weather and the electronics are getting flaky. That ECU is responsible for managing the power provided by the gasoline engine and the two motor generators in the transaxle. The transaxle's behavior is highly dependent upon the correct functioning of the HV ECU. What is the temperature that you set the cabin air temp to?
The electronically controlled hybrid transaxle has the same behavior as a "CVT" only even mechanically simpler: there is nothing that shifts, or physically changes position at all. We might be better able to help if you could take one step back and describe just what you're seeing/hearing/feeling that made you think it wasn't "shifting" right. -Chap
The best way to describe the problem is the the engine rpm seems high for the actual rate of speed that I normally notice
If rpm just sounds a little higher than in some other car that’s normal. Prius gas engine isn’t big and when it’s running it also has to charge the battery so many times it will be running at higher rpms than on traditional car.
Ever figure this one out? I just did a 8hr drive last night after changing plugs, oil and oil filter. RPMs are going extra high especially uphill. Now when driving at a moderate rpm it feels like it's trying to downshift or engine is pulling back. I think going downhill I should have put it in B too. Last year one of my battery cells had went out kept tripping a code it seemed like it went high rpm then disengaging the electric. Could this be the electric side of the Trans going bad now? Also, fuel economy went from 41-42 to 31-35
Could just be the car protecting the battery. When the computer wants to treat the battery extra gently, it just calls on the engine to do the extra work.
I'll place my bet on "another battery module is failing, but hasn't failed hard enough to set a code yet."