Drowned Porsche - Help!

[PureSilver]

Hi all,

I'm a noob hoping to avoid a very costly attack on my wallet by Porsche East London. Torrential rain here in London a few weeks ago overwhelmed the (possibly slightly blocked) drains under our tiptronic 986 Boxster S's tonneau cover and filled the passenger-side footwell with water. We were alerted when the alarm started going beserk at 2 A.M., which some Googling tells me is because Porsche cunningly fitted the alarm/immobiliser module under the passenger side seat in the lowest part of the monocoque, and it was therefore probably full of water.

I disconnected the battery and sealed the car up with a tarp and duct tape until it stopped raining. The following morning I dried the carpet out with a towel as best I could (it was sodden) and set about checking what wasn't working - which turned out to be most of the rear of the car, specifically the power roof, rear light clusters, and spoiler. After a few days more drying out (again, with the battery disconnected) using dehumidifying crystals, more towel treatment, removal of some of the more easily accessible bits of the carpeting over the engine bulkhead, the footmats and the Bose speaker bar, the roof resumed working, and the alarm too.

The car runs and drives just fine, but the rear control units still seem to be malfunctioning. The parking assistance sensors are turned on all the time regardless of which position the gear lever's in, and the reversing lights and brake lights are permanently illuminated, again, regardless of which position the gear lever's in. I've driven it a few hundred meters (to check that the PSM resets, which it does) with the fuses for the parking assistance and those rear clusters pulled, and the car sounds its horn every so often which I assume is to alert others to the fact that my brake lights are nonfunctional. I've also got a 'check reversing light' warning on the dash.

Does anyone have any idea what might be wrong, and if so, what will need to be done to remedy it? I can take photos of the problem and let you know which fuses I'm pulling in order to drive the car, if that would help, and yes, I have indeed blown the drains clear with an air compressor and hose.

Help!

[73 Duchess]

Sorry to hear of your misfortune but happened to my 996 once upon a time. Had to replace the ECU with a refurbished one. I can't remember the cost but it was less than £800 to replace and reprogram. I hope you don't have to but if its got wet it may be the only solution. You're lucky it only went as far as the alarm ECU, later on in its life mine was alert written off with flood damage as it was caught in a deluge in a car park under 3 feet of water, bye bye 996.

HTH

[Rockster]

The way to avoid the costly attack on your wallet was to ensure the drains were free flowing. Sorry but I had to say this to get this point across to other owners who ignore the drains at their peril....

Anyhow, I suspect you are going to have to for every electrical circuit that is acting up trace it and find all connectors that got wet and carefully disconnect the connector and make sure the connector is completely dry and then carefully reconnect.

The making sure the connector is dry is an obvious step. The disconnecting/connecting also removes any surface corrosion that the connector pins/sockets may have developed from the moisture.

[sportsandclassic]

Hi, it may require a new rear control unit fitting as water damaged. Also the park assist unit is toast.

You say it is a 986 Boxster but I think you mean 987 ? As 986 does not have bulb failure recognition amongst other things.

Get it sorted or it may cause roof problems and break some of the components.

Mike

[Ice White Socks]

Strange coincidence as have just had to my rear control unit replaced due to water damage to a blocked rear drain hole. If its a 987 and you haven't got your 'spoiler control module' error yet then there is a chance you might be able to save it by removing the module and drying out the PCB (plenty of advice on the web about how to do clean and dry them). Its not the water that does the damage- more the PCB getting fried if you are putting power through it while wet (so disconnect your battery ASAP). The parts about £200 plus half an hours coding with a dealer/capable independant...

Cheers

[DeeKay17]

Won't your car insurance cover this?

[PureSilver]

Thanks for all the replies, everyone - they are MUCH appreciated. Firstly, yep, that was a typo - it is of course a 987 Boxster S, not a 986 (confused by previously owning a 986 S) - and secondly, if you own a 987, I have to highlight this:

Rockster said:

The way to avoid the costly attack on your wallet was to ensure the drains were free flowing.

It had never occurred to me to check this, but there are a number of drains in the tonneau area. The pair in the front corners of the cover's well are the ones you need to keep an eye on. This part of the tonneau well is very shallow (significantly less than an inch deep), the drains are easily blocked, and combined with parking the car nose-down on a steep driveway they were simply overwhelmed. You need to check these thoroughly at least every three months if you park your car somewhere with falling leaves and the like - blast them clear with an air compressor, or preferably a garden hose with a narrow nozzle jammed in the end.

Anyway:

sportsandclassic said:

Hi, it may require a new rear control unit fitting as water damaged. Also the park assist unit is toast.

Ice White Socks said:

If its a 987 and you haven't got your 'spoiler control module' error yet then there is a chance you might be able to save it by removing the module and drying out the PCB (plenty of advice on the web about how to do clean and dry them). Its not the water that does the damage- more the PCB getting fried if you are putting power through it while wet (so disconnect your battery ASAP).

Sounds like you two know the 987 well. The rear control modules (is there one, or two? I pulled two fuses to disable it/them) are definitely the problem from my troubleshooting. I pulled the battery as fast as I could, but assuming that when I reconnect the battery tomorrow the reverse and brake lights are still stuck on, should I assume they've had it and need to be replaced? I'll Google pulling them out and checking them. Regarding the park assist, the unit actually works fine (graduated beeps correctly etc.), it's just stuck 'on' - I would guess because it's turned on by some facet of the rear control module(s). Do you think that problem is likely to be confined to just the rear control module?

Rockster said:

Anyhow, I suspect you are going to have to for every electrical circuit that is acting up trace it and find all connectors that got wet and carefully disconnect the connector and make sure the connector is completely dry and then carefully reconnect. [...] The making sure the connector is dry is an obvious step. The disconnecting/connecting also removes any surface corrosion that the connector pins/sockets may have developed from the moisture.

Sounds like this is going to be well above my pay grade. If the only wet part of the car is the cabin (which I think it is), am I right in thinking that the only bits I need to pull will be in the cabin too? I can probably pull the passenger seat and check around under there, since that's where the wet patch was, and check for verdigris or other corrosion on the connectors. Anything else I should be on the lookout for?

DeeKay17 said:

Won't your car insurance cover this?

I'm hoping this is going to be one of those things that's cheaper not to lose NCB over than to claim on, but then again, it is Porsche...

[Chromed]

You can try doing what the OPC will have to do, that is dry the car out. If its drivable, go drive it with the roof down, or windows open, park it in the sun etc. just possible may sort itself out.

[was8v]

Best thing to do would be not to power up the malfunctioning module.

Whip it out and open it up if you can and dry the circuits.

Much like you would if you dropped a mobile down the toilet - whip the battery out pronto and put it on top of the boiler for a few days.

If it doesn't work when dry then a good indy may be able to code up a second hand replacement.

[PureSilver]

Update! The rear control units now appear to be working just fine - I have my brake and reversing lights and spoiler working just fine, and I think the parking assist is working OK too!

However, the convertible top has now stopped working. That's odd, because while it initially stopped it then started again, but now - nothing. In order:

1. When I release the latch the microswitch does its job, sort of. The windows drop as normal, but there's no 'convertible top unlatched' warning on the dash.
2. When I push the switch to open the top, the dash displays 'convertible top opening' briefly (about 1s), but sod-all happens. There's no clanking or whirring and the tonneau cover ('clamshell') doesn't move at all, so I'm inclined to think this is an electrical rather than mechanical (balljoint) issue.
3. When I close the latch the windows go back up.

I've checked for blown fuses (there aren't any; cheers Porsche for providing that handy tool) but now I'm at a bit of a loss. At any rate, I've poured some more dehumidifying crystals in (the interior is a lot drier) so we'll see if the top fixes itself or if it has to go to Porsche.

was8v said:

Best thing to do would be not to power up the malfunctioning module.

Whip it out and open it up if you can and dry the circuits.

With the rear modules now seemingly working OK (i.e., the lights aren't permanently illuminated) I figure the car won't run its battery flat overnight, so I've left it all plugged in. Do you happen to know where the modules are, and how I might access them? The car's manual is understandably a bit lacking in in-depth detail and I can't seem to find a walkthrough on Google.

[Pikey66]

An old thread I know, but my boxster started doing this today, windows won't close, brake lights staying on, spoiler system message on dash, and yep, wet under passenger seat. For such a quality brand, there seems to be a lot of design flaws doesn't there, and I only cleared out the drain holes about a week ago. So where else could the water be coming in from?