Could be a long shot but considering a CMOS reset if you haven't done so.
Hello, after doing my most recent updates from Dell Command Update that included a BIOS upgrade, my Bitlocker, which was suspended for the upgrade, no longer works.  When trying to activate it again after the BIOS update, I got the "Starting Bitlocker, The BIOS did not correctly communicate with the Trusted Platform Module (TPM).  Contact the computer manufacturer for BIOS upgrade instructions." Well, I have already upgraded to the latest BIOS for my unit.  Since it wouldn't reactivate bitlocker, I decided to decrypt the drive and then I reset the TPM in the BIOS (even went as far turning it off, rebooting, then reactivating it and resetting it completely.  Also uninstalled TPM from device manager and let it reinstall itself on reboot of the PC).  When I booted back into windows, I tried to turn bitlocker on again and encrypt the drive but I STILL get the same error message about the BIOS not communicating with the TPM. Anyone have any other ideas I can try?  Thanks.
Precision 3460 Bitlocker Problems after BIOS Update