just left on our first road trip and the PSM warning light came on. Of course the fish tool is back home. New to me with less than 1000 miles since I got it and put in a new battery among other things. I was running with the headlights on just because backroads highways….

o’reillys tech says battery is fine, but alternator failed diode test. Drives fine for now, with headlights off.

I have a new 1200 amp battery box and a maintainer I can use to top up the battery between drives.

I have to make a 6 hour stretch back to SLC in a few days.

Any advice welcome! Thanks!

 

If I understand what you're saying (that you have a bad alternator) I'd use that battery box while driving to keep your engine running.
Maybe tap it into the cigarette lighter socket?
Good luck.

 

Yes I think it is indeed the alternator. That is based on the following:
- arrived, maintainer said 92%
- about 10 min later on 3 amp maintainer, 93%
- drove 2 miles lights on, 83%
- after about 40 min, again on 3 amp, 97%

…gonna let that top off overnight.

I am going to make sure the boost box is topped off. I thought if we have issues I’ll plug it in to the DC on the drive home, but mine appears to not do that. It can power a dc device, or be charged using a specific cord, on a different circuit. I do not think this or the Porsche support charging the Porsche battery through the DC circuit (cig lighter) in the car…???

Found an Indy who owns a few Porsches, including a 957 CTTS, and a 911 series turbo, here in Jackson (what are the odds?) hopefully he can set me right before we go.

Could it be a bad headlight controller drawing too much? One of them got flooded a few weeks ago by a bad headlight seal, but came back to life a few days later. I’m waiting to program new ones in with my p-dealer appt in a few weeks.

another new symptom, possibly unrelated, I’m getting “Check Passenger Seat Setting” and the dash light for passenger airbag lights up (indicating the passenger airbag is off), when the seat is not occupied. (I don’t think this matters, but maybe…??? my wife crawled to the back while we were driving. Yes, it seems to come back regardless of restart, or door open/re-shut, and even when she does not start the trip in the seat… maybe it just wants a code reset since it freaked out when she moved seats while driving?)

how often do alternators go on these? (09 CTTS 84K)

thanks all!

 

$2,300 alternator (generator)?

AutoAtlanta Alternator 94860302503

Is it an infinity machine? Does it produce carbon offset green energy while fellating the driver?

hopefully there are aftermarket alternatives. Yes I’d prefer new since the labor here is non-trivial, unless used oem is better than the aftermarket alternatives…

 

FCPEuro has it for $1,400. If it goes bad again they'll replace it for free: https://www.fcpeuro.com/products/por...he-94860302503

It's water cooled, so it's expensive.

In terms of your passenger seat issue, it's probable that the seat occupancy sensor is broken or got unplugged.

 

This will not get you out of a bind now but I bought a Cayenne S with 60K miles that had been t-boned and rolled over for $350 US. I have used so many parts from it on my other Cayennes. It always leaves me with a spare everything. If a starter, alternator, or something like that goes out I just have it rebuilt at a local shop. As many of these Cayennes as they made the local junkyards are full of them, in the Houston area anyway. I had a Bosch starter rebuilt for $90. It works just a good as a new one.

 

^^^i would happily pick up a donor. Got a yard I can drop it in? ;-)

two different testers say the alternator is charging fine. Phew! It looks like the autozone duralast AGM H9 platinum installed ~3 months and ~500 miles ago may be shot. Hopefully it is just a bad cell and not some other additional electrical gremlin.

as for the PSM and seat sensor, they are common low voltage related errors (hopefully).

but maybe: after the last track day, I have to hold the steering wheel left a bit to drive straight. It had an alignment and drive straight prior to the day, and now pulls right unless I hold it left. Hopefully that is just tire wear, could have been knocked out of alignment maybe, but either way hopefully the PSM resets once we get that straightened out (see what I did there?)…

fingers-crossed on the alternator!

 

…and the facepalm award goes to… ME!

Since I changed the battery, nobody else to point this at… the battery terminals were loose on the posts.

All buttoned up now. The battery tests good. I’ll check it again before heading out of town (back home).

fingers-crossed the passenger seat thing clears, and maybe the steering angle sensor too (PSM). Hopefully they were just low voltage issues and will sort out.

in IT (info tech) we have an old saying “ PEBKAC” which applies here. (Problem Exists Between Keyboard And Chair). Except maybe this is PEBSAC (steering wheel)?

fingers-crossed.

 

Wow.... I've NEVER done something that silly....

Nope....

Never...

 

I started to run over my battery (in reverse) just an hour ago.
Forgot my keys and left it by the trunk (not my Cayenne).

 

…do you(or anybody) have a donor with a black interior? I’m missing random bits like the driver side b pillar air vent, seat rail covers, sunglass holder button, tow hook, the panel at the front of the driver seat kind of by the driver’s heels, and more…

and am happy to buy them off who ever cares to part with them…