Last week my starter was slow to crank but I thought it was from the car sitting in the garage for 2 weeks. After a 10 mile drive I stopped somewhere, and then the car would barely turn over. AAA gave me a jump start and it started immediately so I ruled out the alternator and starter since I made it home without any issues. It sat over the weekend and yesterday I put in a new battery. It started without issue and I got a PSM error which is normal after disconnecting the battery...but then I noticed the windows and mirrors weren't working. After driving for a while the PSM error and a new warning "system fault visit workshop" with a picture of what looked like a battery with a lightning bolt that has an arrow on the bottom (ground?) showed up on the dash. I pulled over and cleared the ECU with my Cobb AP of the many codes relating to body and electric sensors that were present. This didn't fix anything so I drove right back home. The codes came right back. Disconnecting ground for a few minutes and reconnecting didn't solve it either.
I'm puzzled because I didn't get any errors at all when driving home with the alternator powering the car, and I've disconnected the battery to work on the car many times without any issues.
I literally took out the faulty battery and put in a new one - nothing else was touched. There were no sparks or smoke and it runs fine.
Has anyone experienced problems like this after a battery change? How did you get rid of it? I really don't want to deal with another visit to the mechanic for something as minor as this.

 

Ive never seen that light that you said popped up but im curious if maybe your alternator or regulator has an issue and is possibly overcharging/undercharging the battery (maybe why your previous battery died). If you have a multimeter you should measure the voltage across the battery with it off (around 12v) and with the car running (should be between 13.8-14.4v). A simple check if you have a meter. I am thinking maybe the high/low voltage is causing some issues with your electronics.

 

I have to ask the obvious: did you get the same spec battery for replacement? If yes, perhaps it's a bad battery. Try swapping it to rule out that scenario. If it's different then look to replace with similar capacity. Coming from owning a BMW M3, which is very picky about batteries and you have to register it as well, I thought changing the battery on the 997 was a breeze. No coding and I even replaced with a lithium battery and love it. Shaved nearly 40lbs and haven't had a single issue.

 

I replaced an "old" battery with a new one because of slow cranking but ultimately I replaced the starter and that fixed my slow start issue. Recently I replaced that new battery with a tiny PC925 and no CEs or warnings. Can you get a PCM voltage reading from the Cobb? How about your fuses?

 

Good idea - I never did check it with the car running because it was able to get the car home with a battery that had definitely failed. Couldn't hurt to know this information. BTW - that light is just an bit-map drawing of a cylinder with a lightning bolt shaped down arrow in the middle next to the warning message, not a separate individual light like the PSM warning.


Yes, Definitely same spec - just AGM type so slightly more CCA (850 vs 800)

Funny you should mention that - I recently purchased a starter because it has been cranking more slowly in the last two months, but not all the time. I haven't had time to install it. The repair jobs are never as much fun as the upgrades, hence - procrastination. I thought it was the starter after reading a few threads here and I'll get to it eventually.

Tomorrow I'll have time to put the Durametric on it and get more detailed information.
I appreciate the replies!

 

I recently replaced my battery and had various faults until I followed the steps for "Putting vehicle into operation" in the owner's manual. There's a section specific for the windows ("Storing end position of the windows" on page 26). Mine is a .2

Hopefully it is something simple.

 

It was beyond simple. It was nothing more than a bit of the random, undiagnosable, unrepeatable fault conditions that make owning a Porsche a truly unique experience. A car I can be 100% certain will get me to my destination every time?!? Yawn...no thanks. I prefer the excitement of tracking down the cause of the inevitable CEL that my Porsche will share with me whenever and wherever it is sure to cause the most inconvenience. This incident turned out to be pretty benign. Just letting it sit in the garage overnight fixed every problem. The sole change I made was removing and reconnecting the battery to the ground cable during some additional voltage testing. After confirming voltages looked good I was done for the day. The next morning when entering the car I noticed the windows were seated correctly and were operating during door closure. I grabbed the key and tested everything - no issues.
Never a dull moment with these cars.