ECM Replacement

If the engine control module (ECM) is replaced, the following procedures must be performed:

1. Idle Learn Procedure-Refer to the appropriate procedure:
   • Idle Learn for the 1.4L DOHC engine
   • Idle Learn for the 1.6L (L91) engine
   • Idle Learn for the 1.8L (L79) engine
   • Idle Learn for the 1.8L (LDA) engine
   • Idle Learn for the 2.0L (L34 GMDAT) engine
2. The crankshaft position (CKP) System Variation Learn Procedure-Refer to the appropriate procedure:
   • Crankshaft Position System Variation Learn for the 1.8L (L79) engine
   • Crankshaft Position System Variation Learn for the 1.8L (LDA) engine
   • Crankshaft Position System Variation Learn for the 2.0L (L34 GMDAT) engine
3. Theft Deterrent-Refer to Programming Theft Deterrent System Components (Scan 100) or Programming Theft Deterrent System Components (Tech 2) . The ECM will learn the incoming fuel continue password immediately upon receipt of a password message. Once a password message is received, and a password is learned, a learn procedure must be performed to change this password again. An ECM which has been previously installed in another vehicle will have learned the other vehicle fuel continue password, and will require a learn procedure after programming to learn the current vehicle password.