"Failure Convertible Top Ctrl." on 987

[RoadHazard]

Following a convertible top repair, my 2005 Boxster S (987.1) now displays "Failure Convertible Top ctrl." whenever I close and latch the top. It's very consistent, not intermittent. Both left and right transmission gearsets have been rebuilt, and the ECU under the left seat has been replaced. The top goes up and down just fine, so it doesn't appear to be a gross mechanical problem.

Another symptom: If I start the car with the top closed and latched, the electric motor starts briefly and attempts to move the convertible top and clamshell slightly. This is similar to the way the car snugs down the top and clamshell when you first close the top, but it shouldn't happen when you start the car with the top already closed. If I release the latch before turning the key, it doesn't do this.

Ideas?

[RoadHazard]

Sanity check, please. When you raise your convertible top to the fully closed position and then latch the manual overhead latch, does the electric motor start up again for about 1 second to tighten the top and the clamshell?

My car (a 2005 Boxster S 987.1) does this, but I can't remember if that's normal or not.

[husker boxster]

Originally Posted by RoadHazard

Sanity check, please. When you raise your convertible top to the fully closed position and then latch the manual overhead latch, does the electric motor start up again for about 1 second to tighten the top and the clamshell?

My car (a 2005 Boxster S 987.1) does this, but I can't remember if that's normal or not.

No, mine doesn't. I'm scattershooting but my guess is you have a bad sensor in your latch mechanism. It's not recognizing the closed position.

[RoadHazard]

Terrific. Thanks for the data point and the suggestion.

Results seem divided about 50/50. Half the people I ask say their car’s top doesn’t move, and half say it does. Weird. I can’t tell if the difference is because of model year or something else.

I’ve checked and rechecked the switch in my windshield and it’s working fine. For example, if I delay closing the latch, the top won’t do its little 1-second tightening maneuver until I do. And my Foxwell OBD scanner shows the switch open/close right on cue.

After replacing the ECU and rebuilding the gear trains I’m running out of ideas…

[pcarsrule]

I found you on RL also ---- did you fix this? what was it?

[RoadHazard]

Originally Posted by pcarsrule

I found you on RL also ---- did you fix this? what was it?

No, afraid not. Still working on it...

[RoadHazard]

Fixed it!

The problem was an incorrectly programmed RCM (the electronic module under the left seat). ECU Doctors in Florida sent me a bad one, then took it back and sent me another bad one, then took that one back and sent me a good one. That's the short version. It actually took more than a year in total and a whole lot of pointless troubleshooting to discover their fault. I'm not a happy camper.

Moral of the story: Porsche changed the convertible top behavior partway through the production run of 987s, so if you replace your RCM make sure it's configured for your EXACT model year, not just any old 987.1 or 987.2. The model year makes a big difference.