Rear trunk release and Spoiler unresponsive after sitting for 2 weeks

Looking for help. Parked my 2005 Boxster S for two weeks, and now the rear trunk will not release (with key or interior switch) and getting a Failure Spoiler Control at 75mph or when I press the spoiler button. Any advice? I’ve only seen one other post but it didn’t seem to have a solution. It suggested sleep/transit mode but no way to get it out of the mode. Desperate! Rear boot won't open after ''Sleep mode&#39

I'm assuming you've checked fuses. IDK offhand which ones, you'll need to check the chart. How old is the battery? Did you have the car on a charger while stored? Odd electrical issues have been known to be caused by a battery which is beginning to fail. Obviously the car starts and runs, so it wasn't caused by a dead battery. I'd then try disconnecting the negative battery terminal. Leave it off for enough time to fully discharge any capacitance. Maybe 30 minutes. That should allow the rear control unit to reset if it is in some odd state. If that doesn't do it, you'll need to have a electronic diagnosis with PIWIS or Durametric. It will localize the point of failure.

Agree with RSchwerer, I will only add this: Sometimes, for unknown reasons, my inside release switch performs better with a lift, then press down action. I was going to replace it then I realized it works perfect each time with that maneuver. It's worth a try, good luck.

Without know more specifics, this sounds like the battery discharged too far. Speaking from experience, these cars will have all sorts of odd behaviors when the battery voltage is allowed to drop. Door latches, trunk latches, spoiler activation, steering wheel sensor limits, go all wonky. One particular odd behavior on mine that should've been a clue, was that the key fob remote started to not intermittently work, and definitely had reduced range. (The ultimate culprit for my battery drain was an aftermarket accessory that was improperly wired to an always hot 12v source, instead of one that was switched with the ignition key accessory position.) Get your battery back up to definitive full charge and re-evaluate.

Update. Fuse 3 is blown. It controls the: “Rear Control Unit TRM30, Rear Spoiler, Rear Lid Release, Two-Tone Horns.” I feel a little bit stupid now. Gonna head down to the auto store and get some more fuses.

Don't feel that way, you didn't give up, you persevered, correctly diagnosed the issue and you are going to fix it with free labor, that's a win all day, every day Spyker.

Thanks mate. I appreciate it. First real car I’m actually getting an opportunity to work on and resolve issues. (I had an MGA previously, and it never once had an issue). Next on the list is dealing with the horrible ride

First of all, something caused that fuse to blow, you're likely not done yet. What's wrong with your ride? My 05 Boxster S has a lovely sports car ride, I particularly like Sport mode. Start another thread and tell us what's wrong?

He's used to an MGA.

That’s too bad, the stock ride is a really good balance of comfort and cornering.

OP if the Rear Control Unit gets wet, you might see weird activity from the items it controls, and/or that blown fuse. Since you just bought the car, take a good look under there and verify that all’s well and dry. Those modules are in a terrible location and doesn’t take very much to get them wet, especially a convertible where a chance downpour could catch someone out and about. In my case many years back the local Porsche dealership left my windows cracked while the car was there for its 20k service. It rained, fortunately not a lot, but enough to get about an inch down in the recessed area where modules sit. I lost my mind but in the end it was no big deal at all and they took great care to make it all up to me, and the car’s perfect to this day. But yea, those modules will do weird stuff when failing! Anyway, check down there and ensure all’s well. Here’s a pic of the area and the connector for the underseat module. Enjoy your car!!!

Whoever lowered the car went an inch too far, maybe more. If the suspension gets that upset when hitting a bump then it is not able to move in a required travel arc. The springs are probably trash and if you still want it lowered (no more than an inch from stock) replace those springs and shocks with a "coil-over" shock kit and the suspension corner balanced.

I had a 2008 Boxster that had rear spoiler issues. I replaced the rear spoiler mechanism to no avail. At some point I removed the controller that resides under the driver seat. Part of the board had crystallin substances on several areas. I cleaned the board, reinstalled, and never had issues again. This control board sits very low under the seat in a recess that can pool water if it is let into the interior. I have seen fixes that suggest you wrap the entire controller in a plastic bag to avoid it getting wet. It was also suggested that you make sure the water drains in the rear area of the convertible top are clear and functioning as drains to prevent water accumulation in that low pocket under the seat. This fix worked for 3 years right up until a driver drove through a red light causing the accident that totaled my car.

This is all awesome advice thank you very much! Funny you should mention the Rear Control Module. On the service from right before I bought the car, the Rear control module appears to have been replaced. I'm definitely gonna look into it and see about water infiltration. I currently have to keep it parked outside for the next few weeks so hopefully it doesn't have a serious water issue. But, I'll get a hose out once warmer weather comes and see about hunting down that issue. I'm guessing I have to remove the driver seat and carpet to get at this module?

Agree. Between the 19in rims and lowering, impacts on Pittsburgh roads are brutal. I met with my local porsche dealership and we explored the various options. Since Ohlins Road and Track coilovers will cost about $500 more than returning to stock, I'll be upgrading to Ohlins

I'm in Pittsburgh, and we have a couple very competent indy's. Not sure what dealership you're working with, but I wouldn't rule out an indy.

Thanks @Spyker1324 and @RSchwerer for the hint on the fuses and the specific pointer to fuse #3. This helped me quickly solve the same problem on our boxster. Cheers!