solcalderon

Hi folks, just finished working on my Boxster (replaced the AOS) and now suddenly the convertible top is stuck halfway open, the shifter is stuck in Park, the trunk and frunk are stuck closed, and my rear spoiler won't raise/lower anymore. We immediately started troubleshooting the fuses and relays as that seemed a good place to start. We couldn't find any blown fuses and we tried swapping the open and close relays for the convertible top. This didn't reveal a cause. My brother removed the drivers seat and inspected the control unit underneath there for cold solder joints or any obvious problems. Nothing seemed wrong there. What should I troubleshoot next?

So...now my Boxster has been stuck on my brother's lift with the top halfway open for a week and we can't figure out how to get it out of park or anything. Kind of a sticky wicket.

Any suggestions guys? Really appreciate any help. Thanks!

deilenberger

It will probably be useful if we know the year of your Boxster.. they aren't all the same.

Kitc2246

Sounds like you killed the battery. Does anything electrical work? Do you have a jump pack or battery maintainer that will plug into the aux socket in the passenger well or cigarette lighter? If the battery will take a charge that's good news. Next would be to use the frunk jump in the driver's side fuse box to open the frunk and get to the battery. See the Admin section in this forum on the frunk.

Marine Blue

Pretty hard to guess but I’ll give it my best shot, battery is shot and causing weird things to happen.....

If this isn’t the issue we’ll need to know more about which model/year you have

solcalderon

I was really hoping it was just a bad battery. We tried connecting a spare battery we had in the shop and it didn't seem to make a difference.

solcalderon

2005 2.7L Base model. Thanks

solcalderon

It still starts fine. But we went ahead and tried connecting a different battery to the car and it seems to be acting the same. Can the battery be outputting sufficient voltage to start the car, but not support the electrical system functions in a stable manner?

Kitc2246

If you changed the battery then I assume you got the frunk open. How did you get it to open? Is anything else in your first post now working? Yes a weak battery causes all sorts of strange issues, but surprised it starts the car. I'd put the battery on a good charger/maintainer over night and see if that solves any of the issues. Hopefully someone who is an electrical wiz on the Boxster can help. If everything worked before you replaced the AOS something may not be properly connected or shorted, but need to eliminate a weak battery first. Once you are sure you have a good strong battery disconnect it for a minute or two and then reconnect. This should cause all of the electronics to reset which may solve your problems.

Finding someone with a diagnostic tool like a Durametric might be your next best step after the battery.

I broke one of the plastic cable connectors for the top on my 09, so I think if you disconnect them you can manually lower or raise the top. Is this a Tiptronic? It being stuck in park is normally a dead battery. Assuming you have your owner's manual there is a manual procedure to unlock it from Park.

solcalderon

Thanks very much for the suggestions. Yesterday I bought a new battery for the car and unfortunately it didn't make any difference. I tried bypassing the rear control unit and applied 12V power directly to the convertible top motor and it worked just fine. So then I tried bypassing the convertible top relays which did nothing. I then I tried bypassing the parking brake switch and the convertible top plunger switch. Neither of these things helped. I at this point I can only surmise that my Rear Control Unit has failed in some manner.

I ended up disconnecting all of the convertible top linkage so I could at least get the top closed manually and drive the car home from my brother's where I was working on it. I figured out the procedure to get it it out of Park and into gear. However, now the speedometer doesn't work and the manual shift function doesn't work. I'm also unable to roll the windows up all the way since my car thinks the top is open. What a mess...

Should I just try replacing the RCU now? It's quite an expensive part so I'm hoping to eliminate any other possible causes before I spend $350 - $400 on a Rear Control Unit. I can't think of any other potential causes of these problems though.

Also...now my windows won't roll up all the way since my car thinks the top is open. Is there any way I can at least force the windows to roll up while I sort the root of the problem out?

Kitc2246

I agree your issues sound like a bad RCU. I'd recommend you pay an independent shop with a PIWIS to validate or find some one with a Durametric or equivalent code reader. Looks like a new one from a dealer is $450. I'd look for a used one making sure I could get a refund if it didn't work. Believe this is under the driver's seat and is notorious for going bad with any significant moisture. Not sure a new or replacement is plug and play, you might need a PIWIS or Durametric Pro.

deilenberger

Since you have a 987 - the Foxwell NT350 with Porsche software would be ideal for testing and replacing the RCU. It's has capabilities for module replacement, and ways to test various components of the top mechanism by actuating them. Cost is less than $200 and you'll have a tool you're likely to use in further adventures of 987 ownership.

The AllDataDIY section on the convertible top mentions two relays that control the opening and closing of the convertible top. They're located in the relay carrier that's buried behind the dash on the drivers side.