RPM slow to return to idle

It could be very normal. You say it happens most when the car is warmed up and in hot weather. What setting do you have the a/c on? Do you have it on LO and run at a high level on Recirc by any chance?

Is the vent on the rear seat blocked when rev issue occurs?

 

how's your 12 volt battery?

 

the battery is linked to almost everything. i would test it just in case. do it in the morning before driving. get a digital voltmeter and check at the battery posts.

 

okay, any relevance to hybrid battery level when it happens?

 

air filter?

 

i don't think i've heard of this issue before. i wonder if there might be any codes stored?

 

I have that come onces in a while but usually occurs when after a brisk acceleration when the traction battery is around 2-3 bars or when ice is in the process of charging the traction battery.
And it feels like the engine is disengaged from the drive (free spinning) and the rpm leisurely comes down.

 

that's what i was thinking.

 

I'm thinking about an overheating HV battery too. The OP says they keep the a/c on always (at 74f/23c) in the Texas heat and that the setting is at RECIRC all the time.

Now I'm sure I've read that by not allowing air to flow through the car it doesn't flow through the HV battery. If the battery is working overtime to cool the car in hot Texas heat and the cold air inside isn't flowing through the battery, then it'll just get hotter and hotter and eventually the car switches to the engine more to protect the cooking battery.

If the Op always does this (as they say they do) then the poor old HV battery is getting hit hard, both sitting in the heat when parked and then working overtime when it isn't.

I wonder if the Op should select Auto and let the car adjust between Recirc and flowing air as it sees fit, though I do wonder if the damage is now done.

 

It's my understanding......the H/V batt. has it's own cooling fan which "Pulls" air from the passenger cab interior......& even when in the "Recirc." mode, some outside air is still allowed to enter the cab interior.......with air/cond. operating, this scenario should supply "Cool" air to the H/V batt.......am I wrong?.......

 

patrick wong keeps his on recirq all the time in arizona.

 

I think some say that setting it to Recirc pulls air from the inside and this minimizes the amount of air that finds its way to the rear seat vent whereas setting it to pull outside air in and pass it through forces more air to seek out the vent to escape. Some also say the AC has to work harder to cool the outside air vs cooling the already cooled air that's being recirculated. My thought is to use Recirc as long as needed to cool the car down and then use pass-through. If you set Auto to say, 74 degrees, then once the cabin is cooled, the air going to the vent should be 74 whether it's recirculated or outside air. However, since the AC is electrical, I don't know how much the "extra" work hurts.