My Oh CRAP moment
 

So here I was. This is what I should call my thread. Wonder if any of you have had your own 'so here I was' moment with the Panamera, and were able to solve.

Over the weekend, I tackled replacing the bearing inside the steering knuckle for my front passenger side. Over last couple weeks, it started making pulsating noises that became very pronounced once I was turning to the left (putting more weight on the passenger front side). By this driving in circles in both directions, noticed front pass side is noisy, determined it is the bearing.
Ordered the bearing. Easy. It arrived, easy. Repacked the bearing since OEM grease in it is to about 200˚F, and I used the Redline CV-2 grease that is a high pressure 800˚F grease. Easy.
Removed the steering knuckle (will be making diy on all this soon from pics I have). Almost easy. No problem.
With new bearing swapped out, took car to do alignment. All good so far.
Drove home without any issues. Wife says she wants to take the PTT for outing with friends. No problem.
Few hours later, I get a text message, the car is not starting and there are messages on the cluster saying PSM, emergency brake, PDK, all errors. Car does not start.

Quickly, I start running through my head, how I did the job, and if I managed to screw something up. Wife starts thinking I screwed up.
I get my laptop, Durametric cable, drive down to the car.
Plug in, try to reset the faults. Not resetting.
Surely, the car does not try to start at all, giving all these exotic errors.
I am starting to raise my heartbeat and pressure.

Oddly enough, I look at the seats, the spoiler, nothing works, no electrical parts appear to be responding to electrical switches.
Could it be the battery? NAH, FOR SURE NOT.

Regardless, I get battery cables, hook up to battery donor vehicle (car used for boosting), hook up other ends to the PTT under the hood.
Try to start. Nothing.
On a hunch. Left donor car running for 2 minutes, then start again. Nothing. However this time I heard a sliver of trying to turn engine over.
Again on hunch, left car connected to donor vehicle for about 12 minutes. PTT started right away.
I was like 10 seconds from giving up to call towing.

Turns out, somehow, the PTT battery got discharged. It was uncharacteristically cold yesterday though, at around 42˚F here in TX.
Drove the car around for about 30 minutes and then returned home, parked in garage, then started the car again, no issues at all.
One thing I did immediately after that, was to reconfigure the cluster to include battery voltage in the multipurpose cluster at all times.
Did not check what it said initially (Should have), but it is there now and will stay there.
Still do not know how the battery could have been discharged. Took the car to work today. We will see if it starts after work. Still cold today.
If you have theories, shoot. Anyways, sharing something that happened related to the PTT last weekend.

How old is the battery? If the battery is at its end of life (approximately 6 years), cold weather will definitely highlight/exasperate the problem.

42 isn't that cold - shouldn't affect the AGM battery much. How long was you wife sitting in the parking lot gabbing with the ignition on and car not running? :)

Had a "oh crap" moment with my Pan, first trip with it, took the family over the mountains ( averaged 26 MPG!) and stopped at the Children's museum the next day, after about 5 hours there we go to leave, car doesn't unlock or respond to the key press? ( it has enter and drive)
Start pressing other buttons and of course it responded top the panic button, now I'm locked out of my car and the alarm is going off! wife and daughter are not looking amused or pleased.

Remember that there is a manual key hidden in the fob, so I open the door and get in, car still won't recognize fob, sit in the car for awhile trying to think, I'm thinking the battery in the fob might be bad, get in and out a couple time and finally the car recognizes the fob!
we need to make a stop at the Japanese grocery store, so I'm thinking at first I will just get anew battery there, then I remember reading about others that have had a problem like this when parked in certain locations ( I had parked next to a large steel shipping container)
and sure enough I tried the car at the store and it worked fine - haven't had a problem since and never changed the battery.....

agree, all these new, high end luxury/sport cars really need the full battery power and they do weird things when they get low. The battery age will tell the story I believe .

Dude! Something very smilar happened to me too! Got the car up and running perfectly after all the fresh maintainance items and drove around for a good 300miles and the wifey asked to drive the car to one of her luncheons... I get the dreaded call of, " um... the Porsche isnt starting".... OMG.... weirdly, this was when i was still using Mobil 1 oil, i noticed the oil level was at minimum... added in a quart of oil and literally, the car starts right up again... weird! lol...happened a few times too... ever since the switch over to Liquimoly, i never had that issue ever again... something i gotta eventually look into though, haha regarding the sensors. glad im not the only one that had dealt with this panic situation too, haha