Hi Guys,

I hope you can help me figure out the issues with my 2012 Panamera RWD V6.

Car was working good. After not driving it for one week, then starting it, the PCM continually tries to reset itself every 10-15 seconds.

The exact issue can be found in this youtube video:

The weird thing is, every now and then it will magically work, usually after being left overnight.

The interesting thing as well is that the trunk will beep 3 times when the PCM is in the rebooting state, whereas if the PCM working, the trunk works correctly.

Is there anything I can do or check? I took the car to Porsche and they want me to replace the whole PCM for $4,000, and replace the trunk module for $700. The battery and charging system seem to be fine. I even bought a new battery, it didn't help matters.

The car has less than 20K miles, I can't believe these issues are happening.

Please help if you can, thanks in advance.

 

Doesn t seem the dealer was helpful? Did they explain anything? I would have suggested battery but you replaced that. My next suggestion would have been to disconnect battery and let everything re set but seems you did that too.

 

I was going to suggest the same things. One possibility is your new battery is weak. Some batteries sit a long time and are not fresh. Take it to an auto parts store and ask them to do a load test.

 

The battery did test out at 12.7V, which according to the tech is optimal. I think it sounds right too, but I'm no expert.

I asked the dealer to clarify why he thought I needed what I did. He stated that the headunit takes the new software and updates, but it keeps doing the same thing as before - restarting every 10 seconds. They said if they try the software fix and it doesn't work, that they then start changing out the hardware, ie the headunit.

He also stated they tried to program the trunk and the unit wouldn't take the programming, thereby beeping 3 times quickly.

However, I keep telling him that when the radio works, the trunks works perfectly too. I think there is something related going on, but they state they don't think so.

Please if anyone can help, it would be greatly appreciated.

Best Regards

 

Sounds like a loose ground wire/connection. Odds are no one would want to tackle the electrical problem as replacing stuff is usually easier to rule things out. The PCM talks to everything so the unit might very well be faulty.