Started up the car yesterday and the PCM would not turn on. No nav, XM or Bluetooth, just a clicking sound underneath the screen. Overnight I pulled the fuse for the PCM and let it sit overnight but this a.m. the same symptoms. Anyone had the same experience or thoughts on what this might be?

 

I think you need a trip to the dealer.

 

+1

 

I would imagine your warranty will take care of that.

 

Anytime you can hear the mech doing that, it's dead.
Be thankful you're not naked.

 

A few restarts may fix

 

Yes. My brother-in-law subscribes to the "self-repairing if you just wait long enough" theory as well.

 

Does this theory also apply to cardan shafts, coils, rear window microswitches, .....

 

Sadly, no. Those are only interwebz rumors. It has only proven to work on catastrophic coolant system failures. If you just add some water and wait long enough, you're good to go.

 

Hi all

I've just suffered a similar problem with an 06 Cayenne S, only 40,000 miles but I haven't had the clicking noise. The screen blinked a few times several days ago but this was resolved by switcing the PCM off and then on again.

However, a couple of days later the start up screen with the Porsche logo remained on the screen for a lot longer than normal, then went through to function as normal, with all the buttons and functions operational. But the next day the PCM wouldn't even switch on.

Any ideas? After only just having the notorious coolant leak fixed by my own mechanic due to Porsche's negligence I really don't want to go and pay ££££ to them to fix it. Any help would really be appreciated. Thanks

 

sorry for digging up the old post, but my 04 CTT has exactly the same problem today as described in the last reply
before this I experienced some problem with either the starter or the battery problem. I had to start the car 3 times before it powered up. it has been like this for a while but PCM always works. right after this the PCM was dead. and after a couple of restarts, the Porsche logo showed up very slowly. then everything worked. same day in the afternoon, it decided to stop working again.
my car has two batteries, and the one in the back is old. also there is always some clicking noise behine the PCM head unit.
I checked the fuses and they seems to be alright.
any suggestions? thanks guys!

 

This is something you will most likely have to learn to live with. it does not happen all the time but it will happen from to time. Replacing the PCM2 will not change this behaviour althought it might reduce it. I for one do not know of a case where this has gone away.

On mine it would happen every few months

The clicking can be a number of things. The CD it bad in the PCM, easy to test, does the maps work and will it play a CD.

Most likely is that its the servo motors on the aircon system vents. Clicking is the least of your problems, mine used to sound like mice on a wheel sometimes.

These are not expensive to buy but a bugger to replace.

 

thanks a lot Mudman2
the map and CD still works and i am sure it is not the reading-disk-noise. it does sounds like a mice on a wheel LOL
I did get
"710
servo motor for defrost flap
Present "
error from my Durametric scan. do you happen to have the part number for it? any idea how to replace it? if it is too hard, i might as well just live with it.

I checked my secondary battery under the subwoofer a couple of month ago and it has "03 06" on one of the post. I assume it was still orignal since my car is 04. but my mech friend's test said it is still okay. the car would not start at first turn sometimes. but my mechanic friends though it is more related to the starter.

 

there are I believe 4 in there. I will check the part numbers, PM me your VIN

955 624 920 00 x 4 may be correct, email sunsetimports for a price

 

12!! thats a lot
I could not find the PM function so I emailed you the VIN. thanks!

so you think there will be no cure to the PCM issue even I replace the 2nd battery?

I just restarted the car. it works now...