I don’t think me_cleaner is compatible with the Core P8600 (Penryn) on the T400, and you shouldn’t trust its output. It was made for new Core chips.
Here is what the libreboot FAQ says:
Before version 6.0 (that is, on systems from 2008/2009 and earlier), the ME can be disabled by setting a couple of values in the SPI flash memory. The ME firmware can then be removed entirely from the flash memory space. libreboot does this on the Intel 4 Series systems that it supports, such as the Libreboot X200 and Libreboot T400. ME firmware versions 6.0 and later, which are found on all systems with an Intel Core i3/i5/i7 CPU and a PCH, include “ME Ignition” firmware that performs some hardware initialization and power management. If the ME’s boot ROM does not find in the SPI flash memory an ME firmware manifest with a valid Intel signature, the whole PC will shut down after 30 minutes.
If you have Libreboot installed, then you don’t have any Intel ME code in your computer. Considering all the things that have to enabled to use AMT, you can be sure that it isn’t functioning.
(By the way, ask these questions on the Coreboot forum, not here)