MacBook Pro sleeps unexpectedly and runs fans at high speed, even after SMC reset
Run diagnostics on the Mac as follows:


Disconnect all external devices
Go to Apple Menu —> Restart
Immediately press and hold down the D key while your Mac restarts
Keep holding the D key until you see the screen listing different languages appears
Click English.  Apple Diagnostics starts automatically.


Common results could be:


Wi-Fi — a failure of the AirPort wireless card (4AIR)
Hard disk and SSD (4HDD)
Logic board (4IRP)
Memory — RAM (4MEM)
External disk (4MHD)
Fans (4MOT)
Processor (4PRC)
Video/graphics card (4YDC)


I'd recommend you see if you have a fan issue: 4MOT