The FCOM is delightfully vague on this matter. Any sustained differential pressure at the elevator feel unit (as caused by a hydraulic or elevator pitot failure) illuminates the FEEL DIFF PRESSURE light and associated master caution. However, the QRH is a one liner saying "continue normal operation". However, a quick look in the MEL tells us this is a NOGO on the ground.
Hopefully somebody with access to the AMM (de facto?) can enlighten me more. There is no indication that the Speed Trim System is deactivated. However, if you are manually trimming, the speed trim is deactivated and remains so for 6 seconds after you stop trimming.
I do find the complete lack of joined up info in the FCOMs and QRH very frustrating...