It can't go below 12 for even 1/10s. Cleaning contact may not be enough. Just in the past week somebody couldn't start their car because the selector switch cable wouldn't stay latched.

Your said there's a hot/cold relation. A connector could be opening or sorting do to temp. Solder joints in the TCM. I would check all the connectors especial in the ebox and if no improvement, I would reflow the solder in the TCM

__________________
2011 E70 • N55 (me)
2012 E70 • N63 (wife)