It will go up but not down automatically (periodically). Sometimes the manual switch works, other times not.

It looked like it was the upper limit switch that wasn't registering. I broke the switch getting it out and so couldn't confirm this guess. I replaced the switch ($45+) and confirmed both switches operational. No effect on the fault.Is there a way to trouble shoot the control module?
I have both PIWIS and Durametric.

Thanks in advance for any help here.
MK19

 

 

Too Dave C.,
Thanks, that did it.
Although controlling the spoiler from the dash button isn't consistent...…..it seems to get confused between the speed based signals and that from the dashboard. I have to turn off the ignition to clear the confusion.

One thing that I learned/relearned is that even though the wing can/did extend to full height (60mm) when it worked at all, doesn't mean that the system is fully fille3d/blead...…. my did fully extend, but the refill/bleed nevertheless solved my problem.

Also FYI; years ago I had to self develop this bleeding procedure on my 996TT...….at that time all the factory offered was "buy a new system" complete.........big $$. Now I was happy to find the procedure in the manual. There's only one real difference that I can see in the 997 system compared to that of the 996TT, and that is the wing attachment is on threaded studs, vs. the 996 that used 1/4 turn zus live fasteners. I nearly broke things on the 997 until I went back and followed the manual step by step, carefully.

Thx for the pointer here,
?s

 

No problem! Glad you got it going. The 6 and 7 TT wing actuation mechanisms are virtually identical. Sadly all the guts, hoses, cylinders, seals, banjos, pistons, motor, drive block, etc. are the same - and thus prone to the same 14 or so failure mechanisms: https://rennkit.com/why-factory-set-fails/