okay i got a used computer computer (PCM)

for the Truck 2006 Chevy trailblazer automatic 6 cylinder which was suppose to be programmed for this truck because i gave the seller the vin number  . Installed it

and It runs ok now but i see the engine light on, so i connect my

OBD2 Scan Automotive Diagnostic Tool Code Reader and get 1 error code P0315 so checked Google and it says 

if the crankshaft position is not learned to drive some which i did for about a hour it like said to do on Google.

But code will not clear i tried removing the battery cable and using the OBD2 Scan Automotive Diagnostic Tool Code Reader to remove the code but cannot clear the code and engine light stays on.

Should i try putting a new crankshaft sensor in.

Not sure because cannot clear the code.

Engine seems to be running fine not sure about gas mileage.