GM Service Manual Online
For 1990-2009 cars only

The replacement ECM comes pre-programmed with vehicle software/calibrations. However, the new ECM must be programmed with the frequency code of the Theft Deterrent Module currently on the vehicle. Refer to Theft Deterrent System in Engine Electrical for the proper procedure. The vehicle will not start until this procedure is performed.

Functional Check

Perform the Powertrain On-Board Diagnostic (OBD) System Check. Refer to Powertrain On Board Diagnostic (OBD) System Check .