GM Service Manual Online
For 1990-2009 cars only

The replacement PCM must be reprogrammed and the crankshaft position system variation learn procedure must be performed. Refer to the following procedures:

    â€¢ Latest Techline information on PCM re-programming
    â€¢  Crankshaft Position System Variation Learn
    â€¢  Password Learn

See the Introduction in Powertrain Control Module Description using the diagnostic functions of the PCM.