Go to the following websites:
https://support.apple.com/kb/DL1823
https://support.apple.com/kb/DL1474
Download and install the firmwares starting with the EFI. Here we are going to restart the same installation so we can run some diagnostics and hardware tests.
Also, two things should be explained before we can continue:
1) Mac OS X has no BIOS but essentially a proprietary version of EFI. EFI was developed by Intel back in the 90s and later a new set of specifications called UEFI were made. UEFI 2.xx was made and development continued under this forum founded offset branch. Apple took in EFI and developed their own versions off of it.
2) The boot processes is different than most computers. A piece of firmware called the BootRom starts the Power-On Self Test and then starts the EFI. The EFI chooses the default disk partition or allows you to choose it manually. After the partition is selected, the boot.efi boot loader then loads the kernel. Apple considers the I/O kit as a part of the kernel. So if the EFI improperly loads the kernel, then you could be having driver issues.
Now to go through a run a diagnostics test and hardware test. Fully power off and power on while pressing and holding the "d" key. This will either run diagnostics or a hardware test. I need you to follow the directions below for either one you booted into. Then do the same except power on pressing and holding "alt/option" and "d" at the same time. Again, reply back with what was found.
While in the hardware test: plug in the AC adapter, choose your language (skip if this doesn't appear), select "Perform extended testing", click the test button, reply any errors (there shouldn't be any) you found, reply everything you saw in the test, and exit after the test by pressing "Shutdown" or "Restart" at the bottom.
While in the diagnostic test: plug in the AC adapter, choose your language and press the "return/enter" key (skip if this doesn't appear), reply back any issues found, and exit after the test by pressing "Shutdown" or "Restart" at the bottom.
If no issues are found, restart and check the Boot ROM Version and SMC Version under " > About This Mac > Overview > System Report > Hardware" to see if it finally matches MBP81.0047.2AB and 1.68f98. Reply if they don't. Then go to Diagnostics under " > About This Mac > Overview > System Report > Hardware > Diagnostics", and there should be a Power On Self-Test and maybe some other tests. Reply any tests that have not passed.