[s-cars] Low boost when engine is warm

[TM]

Hi listers-
I still have a low boost problem in my car. I've checked SJM's
website for tips, and have done this so far:

Checked for codes (ECU temp sensor fault only)
Checked the 10 output channels for problems (nothing exc. ECU temp
sensor)
Replaced multifunction temp sensor (no change)
Replaced ECU thermoswitch (no change)

Okay, what next? I only have low boost once the engine gets hot-
temp gauge reads about 1/3, oil temp around 90C. I get a quick 5psi,
sluggish 10psi, that's it. I was getting a good 15psi with the engine
cold, did not do any extended 4th or 5th gear pulls to see if I got
a full 19psi.

I know the car is in failsafe mode, seems to be some sort of electrical
fault, but I can't find the source of it. I will go through in-depth
with
the Bentley, my VAG-COM and multimeter next.

Taka
will be driving the V70R most likely to s-fest