DTC P1630: Powertrain Control Module In Password Relearn: Testing
WARNING: This page is about a different car, the 2001 Cadillac Eldorado. However, it is still accessible from the selected car via links, so may be relevant.
If engine controls diagnostic system check has been performed, perform THEFT DETERRENT DIAGNOSTIC SYSTEM CHECK under SELF-DIAGNOSTIC SYSTEM. If engine controls diagnostic system check has not been performed, perform ENGINE CONTROLS DIAGNOSTIC SYSTEM CHECK. See BODY CONTROL MODULES - ELDORADO article.