2010 Porsche Boxster S - Gremlins

spydaman

Hi,
I have a 2010 Porsche Boxster S and have been having some weird issues.

Randomly I will come out to the car and radio will be on playing music and my trunk will be popped open. The car is not my daily driver so typically I will not catch the problem while its happening and then the battery will be dead from the radio playing.

I have had the car to the local Porsche Dealership in NJ more times than I can count and they are unable to diagnose the problem. They have tried replacing the radio head unit and several other things to no avail. At this point I think the guys in the service area think I am making this up as they keep giving the car a clean bill of health.

Has anyone seen or heard of similar issues with the Porsche Boxster S or have some sort of advice as to what could be causing this?

Or does anyone know an expert Porsche Mechanic in the Tristate area that may be able to deduce the problem?

Thanks

PF_Flyer

Electrical gremlins can be really elusive! Poking around, I'm seeing similar issues with dead batteries associated with not being able to open the trunk. Can you open the trunk from the key fob? I know it doesn't make sense, but it feels like some kind of "input" is making things happen.

Turning back towards reality, it feels like a short somewhere must be involved.

thecardoc3

Problems like these put the spotlight on just how complicated the diagnostics can be for the techs today. Even if you found someone else that has a similar sounding symptom you can't just jump to the conclusion that was reached on that vehicle and expect to have anything to do with solving this vehicle's issue.

Part of the problem is that modules on the CAN B bus have power all of the time and wake up, or go to sleep based on commands on the data bus, or by a wake up line signal. Porsche does show a wake-up line signal bus wire pin #13 Green at the radio that comes from the Central gateway in the left kick panel, also pin #13. That wake-up bus connects to all the modules on the CAN B bus, so its likely that what ever is triggering an event is causing all of the modules to wake up, have a little party until the battery drains down and then they go back to sleep. The trunk being opened has all of the potential to be a clue as much as it does a red-herring. When some modules start dropping out as the system voltage falls, they can falsely command some of their outputs and things like trunks popping open do happen. But at the same time one has to consider that "maybe" the same command that is causing the trunk to open could be responsible for waking up the bus.

There is software that top techs can get for Mercedes that allows a laptop or PC to be wired into the data bus that learns the ID's of the modules on the bus. Then the car can be shut down and the software set to stand-by and it will record the first module ID that it see's wake up. That helps the technician get a sense of direction with the diagnostics. Off hand I do not know if they make a version of their software for Porsche, but if they do that would be a big help in a case like this.