Heater fan starts running when car is off for a long time...

Are you sure the car is actually switched off? I. e. do you notice if the MFD (screen in the centre) is off?

Do you notice that the dash with the speedo and fuel gauge fails at all, i. e goes dark?

 

Sounds like it’s in Park Ready mode

 

It is not uncommon for people to ask questions about the evaporative emissions self test, which happens several hours after the car is parked. The fan that runs during the test is not really the heater fan, it is a separate one closer to the fuel tank.

If you are positive it's really the heater fan under the dash, then you have something very odd going on. The traction battery contains relays that disconnect it completely whenever the car is not in READY state, so nothing that happens while the car is off can deplete the traction battery.

You mentioned a beep warning. Can you give any more description? Have you pulled any trouble codes?

 

If dashboard lights like transmission position are on, the car is not off.

 

Try pressing and holding the 'OFF' button for 5-10 seconds and see if it finally turns off.

 

if you can't put it in park, that's the crux of the problem. any trouble lites?

 

I had read about something like this years ago. Some Gen2 Prius could have a failure where the car could not shift into park- some thought it was a bad shifter or button on the dashboard while others mentioned the park motor on the transmission. I would not be able to know without someone scanning the car for codes.

If the car isn't in park, it will beep at you - and the high voltage battery can't charge while in neutral. If there is some fault in the park mechanism, you will want to set the parking brake so the car won't roll away. Also, if the car cannot go into park for some reason, then the engine won't start.

I don't know if this is what is happening to YOUR car.

Posted via the PriusChat mobile app.

 

If I remember right, failure to power off can also be a symptom of the combination meter capacitor issue.

 

Shift lock solenoid failure?

 

2003 was the last Prius year to have a shift lock solenoid.

 

can the combo meter be bad without exhibiting any display symptoms?

 

We don't know that it doesn't and remember that aspect is intermittent at the start.

I asked the question, but it was not answered. Or maybe it has and we can't see it due to the poster being moderated.

 

Could be that, but I don't know that a CM problem would prevent the car from engaging park? (I'm assuming that the OP is attempting to use the park button instead just trying to power off).

Posted via the PriusChat mobile app.

 

What did they replace it with?

 

Nothing. No Gen 2 or later Prius has a shifter that locks. They're just little joysticks you can waggle around.

Come to think of it, Prius c does have a more traditional shifter. It's possible they've got a shift lock solenoid in that one.