Well, I just bought this car in December 2013. I was wondering if I could get any feedback or guidance from the forum on an issue with the electrical system. Only happens when connected to Bluetooth and turning off the ignition switch (2014 model has keyless entry) after few minutes the PCM shuts down and drops the call while displaying the battery low voltage warning. At this point all non essential functions are disabled like remote entry, trunk lid remote and automatic function, courtesy lighting, etc., only enough battery power is being conserved to re-start the car. If the engine shut off mode is active in some cases the car will display the battery low voltage warning while at a red light. This failure mode can be reproduced consistently. My dealer is trying hard to figure out the issue but they seem to lack the technical expertise. PNA is involved now but they fail to understand the issue as they only read notes out of a log. Since this model is the first to include the keyless function I was wondering if this issue could be related to this new module. The dealer has reproduced the issue in other 2014's and believe that it's a normal operating process since the new cars reproduce the failure (instead if thinking that all of them have defective sequence). In order to avoid the issue I have to shut down the Bluetooth connection before the car shuts down, so that's what I'm doing. Dealer provided me with a battery tender and mentioned that perhaps I don't drive enough time to charge the battery (real nonsense) but I proved already that even charging the battery overnight the failure persist. I go trough a lot of new cars and I receive the JD Powell surveys consistently. I already have received one for the Panamera and I will be brutally honest not to recommend this car due the unreliable experience I am having.

If anyone has any feedback or suggestions your help would be greatly appreciated. If you are the owner of a 2014 model I would be more than happy to elaborate how to reproduce the failure so you can test your car. Perhaps you would like to know and PNA could use the feedback from more unsatisfied customers.

Thank you!

 

Just saw your posting of the low voltage warning. I also have this problem in a 2013 Panamera w/ V6. Dealer replaced alternator without help then replace the battery. Seemed to help for a while, but problem has resumed. Occurs only after a long drive (when batter should be fully charged!). Interesting comment you had on bluetooth operation. Was your problem resolved?

 

you don t leave the key fob in the car all the time do you?

 

No,keep the fob with me or in the house. Problem occurs when pulling into the garage and starting to unload the vehicle, then all the non essential lights and equipment such as the PCM go off. PCM has a message "Low Voltage shutdown" for about 5 seconds then powers down. Cycling the ignition on to start the vehicle and then off again does not clear the problem. The only thing the clears it is to start the vehicle, run for a few seconds, and shut down again. then the problem goes away until the next long trip. PCNA was also stumped and suggested the battery change 6 months ago, but problem has occurred again. Will revisit the dealer soon...... still under warranty.

 

any resolution?

 

No. Still have "low voltage shutdown" periodically. So far dealer has: replaced battery, replaced alternator, replaced large power relay in rear compartment, updated software.
Still have problem. If I use the engine shutdown at stops, problem does not occur. If I disable this gas saving feature (as I usually do), problem will resurface. Does not seem to be a major problem, but frustrating as all non-essential power is disabled (interior lights, rear hatch lift, PCM, etc.), so seeing anything in the vehicle at night outside is a pain.... The only way to reset the system is to restart the vehicle and run for a minute or two, then shut off the engine. At that point, all is well. Battery voltage when this occurs is over 12.3 volts, so some voltage sensor is haywire.

 

Problem finally seems to be solved. Thanks to the diligence of the dealer (still under warranty), they took it in again and were instructed by Porsche technical service to replace the Gateway computer system. Now the instrument display for battery voltage agrees with the voltage measured by voltmeter on the post in the engine bay, unlike previous checks.
Ready to make a cross country trip again, fingers crossed!

 

Have a safe trip and don't forget to post pics!