HELP! ICE Stays On!

welcome!

what is your battery state of charge icon showing while you drive?

is the heat turned all the way up?

 

If you're not seeing a drop in mpg, tank-to-tank, maybe it is shutting down in more normal usage. What mpg are you getting btw.

 

Can you drive the car in EV? What is the State of Charge of the Traction Battery? Does the Hybrid System Display show battery charging arrows from the ICE into the Battery when the ICE is running? Generally, the ICE will only be running when in Park to warm up or keep the cabin warm. So absent any Traction Battery issues, it might be an HVAC thing, incorrectly signalling that it needs the ICE to produce heat, or whatever logic runs the ICE to complete the warm-up cycle.

 

Not to be snarky, but I think we need better confirmation of exactly what is happening.
Obviously if the ICE is NEVER turning off, there is something wrong. BUT....

If it's NEVER turning off, you should be experiencing a significant drop in MPG.
And also, you'd think if there was a problem with the Hybrid System you'd be setting off codes.

If you haven't already done it, what I would recommend is a long enough highway drive to warm up the engine, and conceivably have the Hybrid Battery charged. Then some suburban driving that SHOULD result in the battery taking over, at least as low speed.

I'd also be interested in what type of driving you do. It's "Synergy" drive, which means in a lot of situations your Prius is using BOTH the battery, electric motors and the ICE.
Does your information screen show the hybrid battery working? On the screen that shows what system's are currently working. The one with the arrows showing energy from Engine, Battery, Regen-Brakes...etc, etc,. I'd be curious as to what it is showing.

It's strange that you would possibly have a failure that significant with the Hybrid System but NOT get a code. How long have you owned the vehicle?

At least keep us posted. Interesting mystery.

 

Maybe. How high above the top mark on the dipstick? One caveat:

Reading the dipstick can be VERY hard. I'd suggest to pull and wipe it, then wait a full five minutes before reinserting for the check. View in good light, and check both sides: sometimes one side is more clean/definite than the other.

 

i doubt it.

how long have you owned the car, and when did it start?

how can you tell the engine is running?

 

I had this same issue. Car sitting for almost two weeks. Went to move out of driveway heater on(low). Seeing on dash charging battery. Noticed its no longer charging battery, engine still on. I stood over it let it idle 60 seconds still on. Went inside car turned off all accessories. Went back under hood still running another two minutes, never turned off. Just a few days ago same thing but this time ice turned off. Battery is roughly two years old. First time I was trying to show my uncle and father let the car finish its warm up cycle then shut off. Darn thing never shut off. Should have slapped myself silly.

 

i had this once last year. left it running in the garage with heat off. it never did stop. maybe a software bug, but i don't think it is the o/p's issue

 

It will run the ICE as long as it needs to satisfy the HVAC request for heat in the cabin, even on low. You have to shut the HVAC completely OFF to cancel the ICE.

 

if one goes from 65F to Low, that should kill the ICE while sitting. it works for me in winter on red lights.

 

just drain the excess oil and see what happens, if nothing, disconect the 12V and reset the ECU.

 

Dealer oil change. The worst.

Its cold up there. Any request for cabin heat comes from the engine. Block off the rad with some cardboard as an experiment. Lots of people in very cold states block off there prius rads for the winter.

 

definitely something wrong. i think it's time for a tech stream scan.

start with the 12v health, maybe the engine is trying to keep it charged through the hybrid circuit.
i know you replaced it, but sometimes they are defective, or need a charge