Heating and Air Conditioning: Technical Service Bulletins

• Customer Interest
  • Body - Broken Rear Window Defogger Grid Detection
  • A/C - Musty Odors Emitted From (HVAC) System
  • A/C B446, B447, and B448 (Low Refrigerant Codes) Set
  • A/C System - Flushing With Refrigerant 11
    • Overview
    • Air Conditioning System Flushing Procedure
      • Overview
      • A.Flush Condenser (On Car) -
      • B.Flush Evaporator (On Car) -
      • C.Flush Discharge/Suction Hose Set and Liquid Lines/Hoses (Off Car) -
      • D.Accumulator (Off Car) -
      • E.Compressor (Off Car) -
  • A/C System - Odor Primarily Upon Start Up
    • Overview
    • Procedure A (Replace Evaporator Core)
    • Procedure B (Clean and Disinfect)
    • Procedure C (Install Afterblow Module)
    • Procedure D (Enabling Afterblow Mode)
  • A/C - Cracked Evaporator Block Fitting
  • A/C - Odor With Start Up In Humid Climates
    • Overview
    • Afterblow Module Wiring Diagrams
      • 1985 to 1993 DeVille/FWD Fleetwood/Sixty Special
      • 1986 to 1991 Eldorado/Seville
      • 1992 & 1993 Eldorado/Seville
      • 1987 to 1993 Allante
  • A/C - Excessive Heat Condition
  • A/C - Insufficient Cooling At Idle
  • A/C - Compressor Discharge Hose Misrouted
  • A/C System - Multiple Malfunctions
  • A/C System - Odors
• By Symptom
  • Abnormal wear/deterioration
    • A/C - Cracked Evaporator Block Fitting
  • Customer Interest
    • Body - Broken Rear Window Defogger Grid Detection
    • A/C - Musty Odors Emitted From (HVAC) System
    • A/C B446, B447, and B448 (Low Refrigerant Codes) Set
    • A/C System - Flushing With Refrigerant 11
      • Overview
      • Air Conditioning System Flushing Procedure
        • Overview
        • A.Flush Condenser (On Car) -
        • B.Flush Evaporator (On Car) -
        • C.Flush Discharge/Suction Hose Set and Liquid Lines/Hoses (Off Car) -
        • D.Accumulator (Off Car) -
        • E.Compressor (Off Car) -
    • A/C System - Odor Primarily Upon Start Up
      • Overview
      • Procedure A (Replace Evaporator Core)
      • Procedure B (Clean and Disinfect)
      • Procedure C (Install Afterblow Module)
      • Procedure D (Enabling Afterblow Mode)
    • A/C - Cracked Evaporator Block Fitting
    • A/C - Odor With Start Up In Humid Climates
      • Overview
      • Afterblow Module Wiring Diagrams
        • 1985 to 1993 DeVille/FWD Fleetwood/Sixty Special
        • 1986 to 1991 Eldorado/Seville
        • 1992 & 1993 Eldorado/Seville
        • 1987 to 1993 Allante
    • A/C - Excessive Heat Condition
    • A/C - Insufficient Cooling At Idle
    • A/C - Compressor Discharge Hose Misrouted
    • A/C System - Multiple Malfunctions
    • A/C System - Odors
  • Erratic Operation
    • A/C - Excessive Heat Condition
    • A/C System - Multiple Malfunctions
  • False instrument warning light/gauges
    • A/C B446, B447, and B448 (Low Refrigerant Codes) Set
  • Inoperative
    • A/C System - Flushing With Refrigerant 11
      • Overview
      • Air Conditioning System Flushing Procedure
        • Overview
        • A.Flush Condenser (On Car) -
        • B.Flush Evaporator (On Car) -
        • C.Flush Discharge/Suction Hose Set and Liquid Lines/Hoses (Off Car) -
        • D.Accumulator (Off Car) -
        • E.Compressor (Off Car) -
    • A/C System - Multiple Malfunctions
  • Leaks
    • A/C - Leak Test
      • Overview
      • General Description
      • Leak Testing the Refrigeration System
        • Overview
        • Electric Halogen Leak Detector
        • Fluorescent Leak Detector
        • Liquid Leak Detectors and Pressure Testing
    • A/C - Cracked Evaporator Block Fitting
    • A/C - Refrigerant Loss Due to Loose or Missing Fitting
  • Loose
    • A/C - Refrigerant Loss Due to Loose or Missing Fitting
  • Odors
    • A/C - Musty Odors Emitted From (HVAC) System
    • A/C - Odors on Hot/Humid Start Up
      • Overview
      • Procedure A (Replace Evaporator Core)
      • Procedure B (Clean and Disinfect)
      • Procedure C (Install Afterblow Module, P/N 25533406)
    • A/C System - Odor Primarily Upon Start Up
      • Overview
      • Procedure A (Replace Evaporator Core)
      • Procedure B (Clean and Disinfect)
      • Procedure C (Install Afterblow Module)
      • Procedure D (Enabling Afterblow Mode)
    • A/C - Odor With Start Up In Humid Climates
      • Overview
      • Afterblow Module Wiring Diagrams
        • 1985 to 1993 DeVille/FWD Fleetwood/Sixty Special
        • 1986 to 1991 Eldorado/Seville
        • 1992 & 1993 Eldorado/Seville
        • 1987 to 1993 Allante
    • A/C System - Odors
  • Poor performance
    • A/C - Cracked Evaporator Block Fitting
    • A/C - Insufficient Cooling At Idle
    • A/C - Refrigerant Loss Due to Loose or Missing Fitting
  • Won't turn off
    • A/C System - Multiple Malfunctions
• All Technical Service Bulletins
  • Vehicle - Engine And Sub Systems Flushing Info. (CANADA)
  • Vehicle - Engine And Sub-Systems Flushing Recommendations
  • Body - Broken Rear Window Defogger Grid Detection
  • A/C - Musty Odors Emitted From (HVAC) System
  • Vehicle - Technical Service Bulletin Updates
  • A/C B446, B447, and B448 (Low Refrigerant Codes) Set
  • A/C - PureGuard 2 Operating Alert
    • Overview
    • Refrigerant Recovery
    • Oil Injection and Refrigerant Charging
    • Additional ACR4 Operation and Maintenance Tips
    • Tank-to-Tank Refrigerant Transfer
    • Excess Air In Tank
    • Pureguard 2 Error Codes
    • Active Flow Control
  • A/C - Tool And Equipment Maintenance
  • A/C - Systems With R12 Or R134a Service Issue
    • Overview
    • R12 System Retrofitting to R134A
    • Servicing R134A Retrofitted Vehicle Systems
    • R12 and R134A Refrigerants Are Not Interchangeable
    • J 41810 Pureguard 2 R134A Refrigerant Monitor
    • Summarizing GM's A/C Service Recommendations
  • Tools - A/C Leak Detector Maintenance Kit Availability
    • Overview
    • Service Procedure
  • Electrical - Wire Probing Device
  • A/C - Info. On the Use of Alternate Refrigerants CFC-12
  • A/C Refrigerant - Contamination
  • A/C - Charging Capacity Chart
  • A/C System - Flushing With Refrigerant 11
    • Overview
    • Air Conditioning System Flushing Procedure
      • Overview
      • A.Flush Condenser (On Car) -
      • B.Flush Evaporator (On Car) -
      • C.Flush Discharge/Suction Hose Set and Liquid Lines/Hoses (Off Car) -
      • D.Accumulator (Off Car) -
      • E.Compressor (Off Car) -
  • A/C - Leak Test
    • Overview
    • General Description
    • Leak Testing the Refrigeration System
      • Overview
      • Electric Halogen Leak Detector
      • Fluorescent Leak Detector
      • Liquid Leak Detectors and Pressure Testing
  • A/C Compressor - Replacement Procedure
  • A/C - Refrigerant (R-134A) Information
  • A/C Compressor Seal Washer - Reference Chart
  • A/C - Blower Motor Replacement Part
  • A/C - Odors on Hot/Humid Start Up
    • Overview
    • Procedure A (Replace Evaporator Core)
    • Procedure B (Clean and Disinfect)
    • Procedure C (Install Afterblow Module, P/N 25533406)
  • A/C System - Odor Primarily Upon Start Up
    • Overview
    • Procedure A (Replace Evaporator Core)
    • Procedure B (Clean and Disinfect)
    • Procedure C (Install Afterblow Module)
    • Procedure D (Enabling Afterblow Mode)
  • A/C - Cracked Evaporator Block Fitting
  • A/C - Odor With Start Up In Humid Climates
    • Overview
    • Afterblow Module Wiring Diagrams
      • 1985 to 1993 DeVille/FWD Fleetwood/Sixty Special
      • 1986 to 1991 Eldorado/Seville
      • 1992 & 1993 Eldorado/Seville
      • 1987 to 1993 Allante
  • A/C - Excessive Heat Condition
  • A/C - Insufficient Cooling At Idle
  • A/T - Refrigerant Schrader Valve Replacement
  • A/C - Refrigerant Loss From Schrader Valve Caps
  • A/C - Refrigerant Loss Due to Loose or Missing Fitting
  • A/C - Compressor Discharge Hose Misrouted
  • Climate Control System - Air Delivery Diagnosis
  • A/C System - Multiple Malfunctions
  • Contaminated R12 Refrigerant - Testing & Handling
  • A/C - Retrofitting R-12 Vehicles to R-134A
  • A/C System - Odors
  • Cooling System, A/C - Aluminum Heater Cores/Radiators