Bigfish

This is a weird one, but just got a 2005 997 and have discovered that when the car is turned off and locked, the PCM is not shutting down fully. It's killing the battery if left off a charger.

The PCM/radio keeps cycling itself like it's in shut down mode and you can hear the disc spin and some very quiet static in the speakers. With a disc out, it's like it keeps trying to shuffle the changer the way it does after the car is turned off and locked (you can hear the tray/eject mechanism moving). It keeps doing so every 15 seconds, basically just rebooting itself, locked with the alarm on and car completely closed.

Has anyone encountered this before? I'm glad to have quickly found my power drain but next steps get tricky.

Not sure what to do in terms of a solution, but it will kill the battery if left for just a couple days. I know I could just pull the fuse but looking to get it out of this cycle so that it shuts down properly.

My local shop reset the ECU to see if it would stop the problem but it keeps persisting.

motopix

I had these symptoms just before my PCM finally died. I bought a "factory replacement" off ebay for $650.

My short term solution before replacement was to pull the D9 (I believe that was the number) fuse in the drivers footwell fuse panel.

Bigfish

Thanks -- so the new unit you got was not doing this cycling once you installed it? I've read conflicting reports so just want to make sure you didn't change anything else during the process, like a battery cable or anything.

motopix

All has been well with the new unit for several months now. I swapped in the new one and fired it up to make sure it worked then pulled it back out to wire in a bluetooth adaptor.

Becker http://beckerautosound.com/ who makes the PCM quoted a flat $950 to replace my broken PCM. I don't know the story on my ebay unit but it was in an factory box from Becker and had a sticker on the side that indicated it was an '08 radio (my car is '06) and was a "factory replacement" and looked brand new but it was probably a refurb.

You will most likely get an error message popup each time you turn on the new unit until it gets a coordinated (handshake) with the car's ECU. But you can just press a button to clear the error and everything will still work fine. My Indy did the handshake for me and you might be able to do it yourself via Durametic if you have one.

Bigfish

Thank you and appreciate the advice. I just pulled the fuse last night while it's in the garage.

I may research if there is any way to do a factory reset on the PCM. It has an iPod control connection and I am wondering if that is something that screwed it up -- I do not know that these came from the factory with that available and I can see adding it on screwing it up. I'll check through the records and see if I can find evidence.

In the meantime I may try to directly wire PCM power to something that powers on/off with the ignition so that it can't get power when the car is switched off. Or, install a relay between the fuse and the box so I can shut if off with a switch. Kind of dumb, but I have other things to get squared away on the car first like a clutch before I get into little things like this.

Luckily this thing is a mechanical gem so far!

motopix

You can do a soft reboot by holding 1-4-8 on the PCM keypad.

ADias

'05s, and for that matter all 997.1s, did NOT have an iPod connection from the factory...

Bigfish

That could be what has sent it into crazy mode then. Basically the iPod functions as a dummy CD and you can use the skip functions, etc. on the face buttons and charge the iPod -- it's more than just an Aux in.

I did make sure to disconnect the iPod before turning off the car but I could see that screwing this all up.

Bigfish

If I am looking at a replacement unit for a 2005 997, does anyone know which PCM versions are compatible? Is it just the 2.1 or are there other version options? (i.e. any kind of upgrade would not be unwelcome).