For 1990-2009 cars

Control Module | Repair | Diagnostic System Check | Schematic
--- | --- | --- | ---
Body Control Module (BCM) | Refer to Body Control Module Replacement | Refer to Diagnostic Starting Point - Body Control System | Refer to Body Control System Schematics
Electronic Brake Control Module (EBCM) | Refer to Electronic Brake Control Module Replacement in Antilock Brake System | Refer to Diagnostic System Check - ABS in Antilock Brake System | Refer to Antilock Brake System Schematics in Antilock Brake System
Engine Control Module (ECM) (L81) | Refer to Engine Control Module Replacement in Engine Controls-3.0L (L81) | Refer to Diagnostic System Check - Engine Controls in Engine Controls-3.0L (L81) | Refer to Engine Controls Schematics in Engine Controls-3.0L (L81)
HVAC Control Module | Refer to HVAC Control Module Replacement in HVAC Systems-Automatic | Refer to Diagnostic System Check - HVAC Systems - Automatic in HVAC Systems-Automatic | Refer to HVAC Schematics in HVAC Systems-Automatic
Inflatable Restraint Sensing and Diagnostic Module (SDM) | Refer to Inflatable Restraint Sensing and Diagnostic Module Replacement in SIR | Refer to Diagnostic System Check - SIR in SIR | Refer to SIR Schematics in SIR
Instrument Panel Cluster (IPC) | Refer to Instrument Cluster Replacement in Instrument Panel Gages and Console | Refer to Diagnostic System Check - Instrument Cluster in Instrument Panel Gages and Console | Refer to Instrument Cluster Schematics in Instrument Panel Gages and Console
Powertrain Control Module (PCM) (L61) | Powertrain Control Module Replacement in Engine Controls-2.2L (L61) | Diagnostic System Check - Engine Controls in Engine Controls-2.2L (L61) | Engine Controls Schematics in Engine Control-2.2L (L61)
Transmission Control Module (TCM) (4T40-E/4T45-E) | Refer to Transmission Control Module Replacement in Automatic Transaxle - 4T40-E/4T45-E | Refer to Diagnostic System Check - Automatic Transmission in Automatic Transaxle - 4T40-E/4T45-E | Refer to Automatic Transmission Controls Schematics in Automatic Transaxle - 4T40-E/4T45-E
Vehicle Communication Interface Module (VCIM) | Refer to Communication Interface Module Replacement in Cellular Communication | Refer to Diagnostic System Check - Cellular Communication in Cellular Communication | Refer to OnStar Schematics in Cellular Communication