drfous

never mind.

utkinpol

yep, needs a reset with PIWIS. same trick happens when battery dies very slowly as ECU starts to turn off all components to preserve power.

it never happens if you just disconnect your battery, and I am not sure if simple reset (battery disconnected for 10+min) will fix that.

John52

I have been removing my battery for winter storage for the past two years (now on winter #3). My experience would support what previous poster "utkinpol" said, i.e. if you disconnect and re-connect a fully charged battery as per the instructions in the owners manual, there are no issues. Th only thing you have to do is re-program the windows , which takes about 5 seconds.

Carrera Mike

I know this is an old post. Just want to confirm what Larrtrk mentioned above. "Handover Procedure with PIWIS fixed this for me.

I removed the battery for 2 days a week ago and when i installed it back everything worked fine except for the Homelink and Seat Heaters. Quick trip tot he porsche service center and did the "Handover" with the PIWIS did the trick.

By the way, I didnt even had to reprogam the Homelink buttons. after the PIWIS they worked right back up!

**and oh, Durametric does not have "handover" program.

Thanks Larrytrk! Saved me from some frustrations

BionicTulip

Bumping an old thread because this is the correct diagnosis for a problem that probably happens more often than we realize.

I bought a used 997 (2006 C4S Cab) that had just been in for work on the starter. Dealer must have disconnected the battery and not done the handoff properly.

Heated Seats and Homelink garage door openers were totally non-responsive. The PCM "dealer handoff" flash immediately fixed the problems.