So, I've had my PCM reboot a few times over the last couple of months while driving..not a big deal, but annoying.


Today, I took the key out, left the car, then I forgot something and went to the passengers side door to get my things, and I noticed the CD was still on...HUH? If I didn't catch it, I bet my battery would have been dead in the morning.


I know a few of you who have had dead batteries. I'm wondering if this is the issue.


So I guess the question is...why? I know there is a software update cause I haven't brought in my car in about a year since I bought it, but what would cause this issue from the original software?




2014 991s

 

Not sure what happened.
However the PCM turns off after about 30min, to prevent battery drain.
Perhaps you have a sensor problem with the car not registering that you opened the car door to exit, which should have turned off the PCM.

 

I don't think so. Isn't the Bose suppose to shut off when you take the key out?

 

probably not a cd working but internal cooling fan... after key is out screen will black out but unit will "go sleep" after 5 to 30 minutes . so if you press button to power on it will not boot again showing porsche crest - it will wake as any notebook do.

 

It is highly unlikely that something left on overnight like you observered is going to kill the battery unless you have a degraded battery.

We are talking about a 750Ah battery. So even if you left the ignition on and the car was pulling 10A, it would last for 75 hours. I'm guessing the current draw from the CD player with no audio power output as you observed would only be a couple of amps at most. Hardly enough to flatten the battery in a few hours.

I believe there are some folks who have had some weirdness with enter and drive being left alive somehow because of a key in the proximity, but still unless you have a bad battery I doubt even overnight you would have a dead battery just overnight.

My own experience is I left the ignition on acc over night with the reading/map light on, and it was just fine the next morning.

Things like headlights are another story, the current draw is pretty high, so you would probably be out of luck if you left them on somehow overnight.

As far as the CD on after shutting off, not sure I've seen that. But even if it did I doubt it would be an issue..

 

I believe the radio stays on after removing key and waits to shut off after driver door open.
If you open door before removing key then the key removal would shut off radio.

I cant test my car as I am out of town.
Does anyones car behave different?

Also, I think even the ignition will shut off, after about 30 min, if left on accidentally.
But that is with Entry and Drive.
Key operated cars may be different.
I do need to test to confirm this one.
Just thought I saw it hapen before.

 

For entry and drive, if you turn off the dummy key, the radio will stay on until you open the door. If you don't open the door, the radio will stay on but will shut off by itself after about 10 minutes or so