My Boxster's electrical system is screwed up.
 

My 2001 Boxster has been outside during the deluge of rain in Northern California, and the other day while driving the interior lights stayed on, and after parking, it wouldn't start. Wouldn't turn over. Finally, after repeated tries, it did start, but after I got it home, it was dead again. Nothing seemed to work. Had to use a jumper cable between fuse box and frame to even open the bonnet. A day later, it started again and I took it to my mechanic, who thought there was a problem with the drainage in the box under the driver's seat, and that was the cause of the weird electrical issues. He tried to dry that out and I brought it back home. It now starts okay, but pressing the remote button that's supposed to lock the car instead opens the trunk. And if I lock the driver's door by turning the key, the passenger's door doesn't lock. So I got problems.

Any insights or suggestions? Thanks.

Follow up. My mechanic said it was the control module (I think also called the "immobilizer"??) which is located under the driver's seat. He dried out that area as well as possible and made sure the drains were open. We've been out of town for a while and just got back, so it's time to get things fixed.

As I mentioned before, the rains here have been torrential, and I had left the car outside. For a couple of weeks, the inside of the windshield has been very wet when it rains - so I suspect the drains under the driver's seat were indeed plugged.

At this point the engine will start fine, and the windows - which for a while didn't work - now do. The main immediate problem is that there's no way to lock the car. The remote doesn't work - opens the trunk instead. Physically locking the door doesn't also lock the passenger door. And the key lock on the dash is inoperative.

It seems that I'll need to either get a dealer try to reprogram the module to my key (which probably won't work) or replace the module (which is expensive). Any of you had this problem? Any suggestions?

Been there, done that. You will likely need a new immobilizer. If you're at the dealer they will want to take the seats out to get the carpet out so it can dry. Not a bad idea to do that, just that it comes at the dealer's hourly rate. With a new immobilizer you may need new keys as well.

Two things. Check your front and rear drains so that this doesn't happen again.youi may want to follow this link

http://www.ecudoctors.com/

Other forum uses have recomended them before. If they can fix it you'll avoid the cost of reprogramming and new keys. An indie might go for this, not sure about a dealer.

And get your checkbook out.

As a precaution for others to consider when they cringe at the costs involved:
1 . Drill at least one drain hole in the floor close to the immobilizer box .Make sure you locate the hole so you don't drill anything else !
2. Consider using a rubbermaid type tub for the immobilizer, a ziplock bag or one of the pro made waterproof boxes mentioned in Search.
3. Make sure there are screens over all the drain holes or they will plug up again and again & .......You can buy pro ones or make your own.
And if you have just incurred the expense of repairing this problem, all the items above may be attractive ? Part number 987 561 487 00. Could not find them on Pelican but Sunset and ECS have them
http://www.ecudoctors.com/porsche-996-boxster-waterproof-immobilizer-case-enclosure.html
http://forums.pelicanparts.com/boxster-cayman-forum/819818-new-idea-porsche-boxster-immobilizer-clu-water-proof-case.html

It is possible to remove the seat, remove the immobilizer, dry it off, clean it with electrical contact cleaner, inspect the solder joints, inspect the wire contact points, put it back together and find things working again. Search the forums.

By all means be proactive but if the worst happens, don't give up without trying the cheap solutions.

And consider an outside cover given that downpours are happening even more frequently. Even if you only use it when serious rains are predicted, it is far cheaper than replacing an immobilizer that is coded to lots of things like door locks and VINs etc.

Some suggest total immersion in iso propyl alcohol . Search first !

Blow out the convertible top drains!!!

If you can, put the immobilizer in a heavy duty zip lock and pull a vacuum on it to dry it out or take it to a Verizon store, they have a vacuum box for drying phones. it costs $10 to do.

If I buy a new immobilizer, will that need to be reprogrammed by a dealer? If so, any idea how expensive, ball park?

What will work after installing a new immobilizer? Will the engine even start before reprogramming?

Also, how big a job is removing the driver's seat to get to the area? If I go the EcuDoctors route, I might have a try at it.

Removing the seat is no big deal. Four torx head screws. If you don't have a female Torx socket a standard socket will work and not bigger the screw heads too badly. Disconnect the battery first or you will trigger an air bag light. The hardest part is figuring out how to undo the plug from the seat into the immobilized. If I recall correctly, you have to lift and remove a tab and then slide the plug apart. May be able to find a video on how to open this

A New immobilizer will have to be reprogrammed. Three parts work together: the transponder in the key fob, the Central locking unit (immobilizer box under the seat), and the DME (engine computer in the rear trunk). All three of those parts have to have a matching code for the car to start. The only part that can be electronically reprogrammed is the DME, so if you just swap one of the three, your car will not start.

Three alternatives to a new box and reprogramming:

-ECU Doctors can repair your central locking unit (CLU).

-A smart electronics tech can take the part of your CLU that has the immobilizer code and swap it into a good unit. *edit: I don't think this would fix your fob button issues.

-You can get a complete set of key fob, CLU, and DME from a similar year/model car and swap it together into your car. The minor issue with this is that the DME will retain the data from the donor car (such as VIN, over revs, hours... ) unless it is reprogrammed to your car's data.
I have a set from a 2001 base: 1 fob, CLU, DME. PM me for price if you want to try that route.

As I've been exchanging PMs with Wilson95005, I remembered a few discussions from the past that I thought would be good to post here for anyone's future reference.

Removing the seat:
This pictorial DIY on Rennlist is a great reference for the removal.
Pages 1 & 2: Rennlist Member Gallery :: DIY GT3 Seats Install

Making cheap spare keys (no electronics in the key):
http://986forum.com/forums/diy-project-guides/56448-diy-making-cheap-spare-keys.html

Cheap keyless entry:
http://986forum.com/forums/diy-project-guides/56773-3rd-party-keyless-entry-diy-why-not.html

Pictures of imari's corroded Central Locking Unit that was cleaned and worked again ...until it was flooded again. Be sure to keep the drains by the engine bay clear.:
http://986forum.com/forums/performance-technical-chat/62650-need-immobiliser-advice.html