Why might the ICE continue running for ~5+ minutes while stopped?

Mine has done this to me a couple of times.

(2017 Gen 4, 70K miles)

I assumed it was because I'd been using the A/C pretty heavily (also in Texas!) and only a 7 or 8 minute ride in to work.

This morning it was raining pretty heavily, so I was using lights, wipers, defroster in addition to A/C.

I don't like to shut off the ICE if it's running, but it takes at most a minute or three of waiting in my case.

I'm thinking it does this because I'm done with my "highway" driving when I get into town, and I creep around pretty slowly staying in EV mode - so it probably draws the traction battery down far enough that it feels the need to charge it up again.


It doesn't do this on the way home - which is high-speed drive to the driveway and only a minute of EV to pull in and park.

Interesting to hear what others say.....

 

Check or have your 12 V checked.

moto g(7) power ?

 

Our is new (two months old - OEM)

 

I’ve had engine run-on a few times, usually after a longish drive, on hot day. Just a matter of a minute or two. If engine is fully warmed I wouldn’t worry about shutting down whenever.

 

Prius takes care of the 12 V if it's drained when I'm programming without a charger it will deplete the HV as soon as I start. You have AC on but the OP said off. (That's suffering in 93 degree heat for 15+ mins). How long is your engine running when you stop?

moto g(7) power ?

 

I've had this occur and usually it happens when the HV battery is hotter than normal. It's not as efficient as it should be.

Another occurrence I've had is when the HV battery terminals have lots of corrosion on them. When it's covered with corrosion, it will take much longer for the engine to shut down at a stop.

 

for those who think ice is staying on to charge a low 12 bat, I was told the hv bat will charge it up and ice shouldn’t stay on for that. About 3 people replied to my comment when I said ice was charging the 12v bat

 

Glad they like you to respond. That makes sense. My experience was with Ig-ON but engine-OFF, (READY-OFF).

(There I go transferring my problem onto others again. ZIPPING up my lips proverbially).

moto g(7) power ?

 

If you have a multimeter:

After driving or charging the battery. Turn off the car and turn on high beams for 30 seconds. Then check the voltage at the battery terminals. (Quite a simple check Toyota prescribes on techinfo.com. I forgot the break points off hand I'm afraid).

moto g(7) power ?

 

That does not automatically mean:
That it was fully charged when installed.
That the car is keeping it charged.
That it hasn't gone bad already.

NOT checking that first can sometimes turn out to be a BIG mistake.

BUT.....at ~12 years old, I suspect this is an early warning sign of the HV battery getting weak.
HEAT makes all batteries age faster.

 

perfect

 

I’ve had it stay on in 90+ degree temps in CA. 2012 with 160k. car was definitely already warmed up, (I do the same thing with letting the engine cycle off before shutting power) but in this instance I had A/C working for most of that drive and was in direct sun. I eventually shut the car down… on next startup it didn’t persist. I’ve maybe had it happen twice.

 

I’m almost 100% sure that’s a good battery. It should be at the terminals per the manual but due to the length of wire there might be slight less voltage where you measured.

Even if the engine turned off as long as car stayed in READY it is charging/maintaining the 12 V.

EDIT-. Those aren't readings in READY are they?