HELP! Possessed '06 Boxster S
 

Hello all!

I need some advice / guidance ... I started up my '06 Boxster S this morning like any other morning. I got about a mile from my home, and the car stated going crazy... The car alarm went off, the spoiler came up, the convertible top hatch opened all the way, windows opened, and I got two errors on the dash info center. The errors were "System Fault" and "PSM Failure".

I pulled over, turned off the car, (the alarm kept going), waited about 2 minutes and restarted (I'm a computer tech....). That did not help. I drove the car home, and contacted my mechanic. He found it all very odd, and he has always taken great care of my baby.

I had it towed to his shop, and he diagnosed it as an alternator ($1350 installed). I got a call about an hour later saying he could not get the convertible top to respond or get the hatch to open again, thus preventing him from getting to the top of the engine compartment. He tried for about an hour before he closed up shop, and was unable to get it to move.

He is of course closed for Thanksgiving, so I won't hear back from him until Friday, and the alternator won't be in until Tuesday.

While I trust my mechanic, and he has been working on Porsches for 20+ years, I'm worried that something more then the alternator is going on. It was pouring rain when I drove home last night, so I am wondering if this is related. I've driven in the rain before of course...

Does anyone have any idea on what else I could be looking at :confused:? I've read some other posts, and nothing seems to match up 100%.

Sorry for the long post, but I'm sitting on pins and needles wondering what else is going on with my baby.

I would check the battery connections first

I would check for water under the driver's seat. That's where the ECU lives and if you have a drain plugged, water collects under the seat. Since you're in IT, you know ECUs don't care for H2O. A wet ECU will cause lots of odd electrical issues. Generally you have to let the unit dry out before running it, which didn't happen in your case. You may now have a damaged ECU.

I haven't done an alternator replacement, but you should be able to get to it from the panel behind the seats. Don't quote me on that.

Good luck and welcome to the forum.

Thanks for the info ... I was thinking ECU too. My mechanic is doing the alternator (assuming he can get the hatch open), but I'm going to call him Friday morning and ask if he checked the ECU. I have a sinking feeling that is not an inexpensive repair :(

I've done a few projects on my own, but this one screamed call in the experts.

Pull the seat (4 bolts) if there is water in that pan or if it feels soaking wet disconnect he battery, take it out and let it dry out for a week in a good warn dry place...do not reconnect the battery before everything including the seat is hooked back up.

Comment removed.

When my alternator started going out I had a bunch of panel light warnings come on too. There were lights coming on I never knew existed. Long story short, I read the forums and symptoms and decided to replace the alternator.

There is one cable most instructions I read required removal. The access to the cable is from the top engine cover. Instead of doing that I disconnected my battery and went about the normal alternator replacement process. A few notes..

- I did not remove the top engine cover
- I did not remove the passenger seat to access the panel. I'm a fairly big guy and I was able to maneuver around
- I did not buy an original Bosch alternator, I bought one from O'Reilly for about $160
- I did not go the route of replacing the regulator only
- I did not give up when I thought somebody cruelly welded the alternator in place
- I did sigh in relief when the automotive parts store verified my alternator was bad

The alternator was my first dive into the Porsche engine and if you have or can borrow a few tools it's a good confidence builder. At least it was for me.

Good luck and let us know how it goes!

Another thought
 

Im not sure how the alternator or AC Generator on the Boxster is much different than any other late model car. Before you do anything (except check for water under the seat on the ECU) with the car running get a VOM and check the voltage across the battery....if it is 13.8 to 14.4 volts or so your alternator is most likely working properly. This will only take a few minutes to do. If you do not have a VOM (Volt Ohm Meter) go buy one at Walmart, Lowes, Home depot or even Harbor Freight.....every car/home owner needs a VOM and know it's most basic functions.

https://www.youtube.com/watch?v=bF3OyQ3HwfU

I didn't think to check the voltage before it went to the shop, kicking myself for that now. My first guess was the ECU, and I was surprised when my mechanic said alternator. What does worry me is that if the alternator was putting out enough power to run things like heated seats (I tried turning them off while it was going crazy), it should have enough output to run the computer.

While I didn't take out the seats or anything, I did check the interior for any signs of leaks and the floors were dry.

Hopefully I will find out more in the morning, if they can find a way to get into the convertible hatch... I will post as soon as I hear something.

Thanks everyone!

DVM check only tells part of the story. It will not detect a bad VR diode (or two). Need to pull alternator and have it checked out. I'll bet the OP has a bad regulator. $50 and a 1 hour DYI.

True....but everyone needs a DVM and it is a very quick test

Thanks for the info everyone!

My mechanic finished replacing the alternator, however the convertible top is still not responding. He also replaced the "reaction rods" for the top, as I guess one was damaged with the top tried to open on its own.

My mechanic seems to be at a loss as to why the top won't open, however he said he thinks the computer needs to be "Re-sequenced". Does this sound right to anyone? :confused: He said I will have to take it to the dealer to have this done... I'm less then excited about a dealer trip after just doing $2200 in repairs.

My concern is that I am going to pick up my baby in the morning, get half a mile down the road, and have the car go crazy again. I just can't wrap my head around an alternator having caused a temporary computer problem, and it only effected the convertible control programming.

I agree with the others who said check the immobilizer under the drivers seat. You'll also need to take it apart to get a look at the circuit board. I'd also look for loose or corroded grounds.

check the covertible top drain holes, like the others said it is likely your immobilizer. Even if the floor is not currently wet you should pull the seat and pull out the alarm control unit (immobilizer). Even if the drains are not clogged it does not take much moisture such as leaving the window down for a bit on a rainy day to get enough moisture in there to corrode the connections.

Pull the ecu and clean any corrosion you see, open it and clean inside too with electrical parts cleaner, if it gets worse the alarm control unit will need to be replaced by the dealer. Cost is around $700~ parts/labor, although you may need a new key fob which will also need to be programmed... those can get pricy too~
Good luck
J