PCM 3.0 issues on 981 Cayman

[adamr_ZA]

Hi all ... been a while and back in a Porsche ... smaller one this time around .... have a 2013 Cayman PDK and having some weird problem with the PCM module ... out of the thirty times id start the car it will work fine and turn on ... but there will be one instant where it just wont come on, it will be dead no radio, nada ... switching on and off doesnt help and it seems after some time will it work again ... only after switching off the car and on again ...

if it is working while driving no issues ... only happens on car switch on or ignition on that it does this ...

i have tried changing fuses, and did not notice that with the pcm not turning on if i pull the fuse out and in again then it works again ... it has been at Porsche and they dont find any faults on the diagnostics and of course murphys law it all works fine when at the dealership

anyone else experience such issues with their PCM 3.0 module?

i have ruled out battery as the voltage is fine at 13.5V - 14.5V

[adamr_ZA]

There is a campaign out on the cayman 981 regarding the MOST and cluster... The car was reprogrammed and so far it's seems all good... If anyone has a similar problem maybe the campaign fix will sort it out

Edited April 30, 2014 by adamr_ZA

[adamr_ZA]

Ok so the campaign didn't help... The car this morning did it again. Started the car all fine. Drove to the local gas station to withdraw money from the ATM, maybe ten minute drive at most. Got back to car started it and Pcm dead... Been using the car everyday for everything... I don't understand the really rare occasion it does act... Do have a car charger in the 12v socket for the iPhone and the iPhone is paired via Bluetooth to the car

Car is booked in with porsche... But id really like to know what could be the problem? Logic says it's not anything physical wrong... Else it would do it more often or at least become more frequent... This happens very infrequently

EDIT: ok its actaully PCM 3.1 ... my bad ... the version number on the firmware is 12112954 ... i am able to replicate the issue ... which is a start ... so i cycle through the following maybe like 20 times

1. turn off, wait for all systems to be completely off

2. alarm on (lock car)

3. unlock car

4. ignition

eventually on the twentieth cycle (maybe even more) the PCM wont come on ... in the cluster the audio and phone is not available ... there is power to the PCM module as i can see the backlights on the buttons of the PCM module light up, but the screen is just dead and wont come on, as if not enough power to the module !? ... i need to remove the fuse wait a little, replace the fuse and it works again ... although the first time i remove the fuse and replaced it the screen had a black line in the center ... left the fuse out for more than a minute replaced and its fine

is it a ground issue?

Edited May 9, 2014 by adamr_ZA

[rmmaso]

Yesterday I had my radar detector plugged into the 12v socket and noticed the voltage immediately drop to 12.5v from a normal 13.5v to 14.5v. This seemed a little extreme. After parking and removing the radar detector, I returned to the car about 2 hours latter and, while it was not dead, it was as if the battery was on its last legs. After 3 tries it started up and soon returned to normal voltage of 13.8 without the radar detector attached. I have to wonder if it is a problem with the 12v charger. My Cayman S has also been reprogramed.

[DOMINIQUE REYNDERS]

Was here a solution for your problem ? I have sort of same trouble with Boxster 2015 

radio is ok , navi is not starting , searching cards ............hours