GM Service Manual Online
For 1990-2009 cars only

These diagnostics are included with Engine Controls for HVAC Compressor Controls System Diagnosis and Circuit Operation. Refer to Powertrain Control Module Controlled Air Conditioning (A/C) Circuit Diagnosis for the 3.5L engine and refer to Powertrain Control Module Controlled Air Conditioning (A/C) Circuit Diagnosis for the 3.8L engine.