m a x i m u s

hi everyone.

this is my first post, so to introduce myself, i have a 2008 cayenne v6, and i have a wonky PCM.

about a week ago, the screen started flickering, and as of yesterday, it doesn't really respond well to commands (such as the on/off button), and also all the memory settings have been wiped, including the clock. at first i thought the screen was going bad as others have posted about, but now that the clock and radio station presets and even the nav are all reset (ie, memory has been wiped), i am thinking this may be a battery issue. i checked the fuse for the PCM and it looked fine. i even swapped it with the spare just to be sure. the dash reads a smidge over 14V for the battery, however, so maybe it's a loose power connection to the PCM itself?

can someone shed some light on this for me, please?

thanks a lot!

CAVU

1. Are you always using the same key?

2. Are you noticing that the presets stay with you while you drive? How long does the car have to sit before you notice the loss of the presets.

3. Trying taking a voltage measurement about 5 minutes after shutdown and then after the car has sat overnight and let us know what they are.

4. You can take the car to an Advance Auto or Autozone and they can test the battery. I think they can use the jumper connections under the hood without damaging anything or having to access the battery itself.

mcbit

If the only thing which is being affected is the PCM I would suspect a connection issue withe the PCM, either externally or internally

m a x i m u s

today my PCM screen continued it's flickering ways, and now seems completely dead. no lights, won't turn on, and doesn't really make that "whirrr" sound when i open the door anymore (i assume that whirring sound was something related to the cd drive or something). i think i may try to pop the unit out and see what's going on, but ultimately, probably will have to take it somewhere to get it fixed, unless Porsche only sells whole units and not parts ...

anyone have a good indie shop they can recommend in the West LA / Beverly Hills area? or a place like beckerautosound.com out here in socal?

thanks.

scottl951

The whirrr sound when you open the driver door is the fuel pumps pressurizing the system before starting. You don't hear this anymore? Car starts/runs fine?

m a x i m u s

There seems to be two different whirrs. I still hear the one that seems to be coming from under the car (fuel pumps?), but only sporadically do i hear the whirr from the PCM ... There is definitely a noise coming from the unit.

m a x i m u s

I'm going to just take it in to a local audio system repair shop and see what they think; I've been known to create more problems as I get deeper into the trouble shooting phase. I'll report back what I find.

Dilberto

The whirring sound is the power drivers seat. It sounds the car battery is near dead. Get it tested now...