GM Service Manual Online
For 1990-2009 cars only

The heating, ventilation and air conditioning (HVAC) system is divided into 2 separate sections. The first, Heating, Ventilation and Air Conditioning, has all procedures that pertain to a HVAC component or function that is not specifically associated with the manual control system. The second, HVAC Systems - Manual, has all procedures specific to the manual control system.

Begin the system diagnosis with the Symptoms - HVAC Systems - Manual .

Review the Description and Operation information to help you determine the correct symptom diagnostic procedure when a malfunction exists. Reviewing the Description and Operation information will also help you determine if the condition described by the customer is normal operation. The HVAC Description and Operation information is divided into the following procedures:

    •  Air Delivery Description and Operation
    •  Air Temperature Description and Operation

The Air Delivery Description and Operation contains the following topics:

    • HVAC Control Components
    • Air Speed
    • Air Delivery
    • Recirculation Operation

The Air Temperature Description and Operation contains the following topics:

    • HVAC Control Components
    • Heating and A/C Operation
    • Engine Coolant
    • A/C Cycle