GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Pontiac 🢒 2000 🢒 Bonneville 🢒 Body and Accessories 🢒 Data Link Communications 🢒 Symptoms

Important: The following steps must be completed before using the symptom tables.

  1. Perform the Diagnostic System Check before using the Symptom Tables in order to verify that all of the following are true:
    2. • There are no DTCs set.
    • The control module(s) can communicate via the serial data link.
  2. Review the system operation in order to familiarize yourself with the system functions. Refer to the following:
    3. •  Dual Zone Air Conditioning (A/C) System Description
    •  Operating Modes
    •  Purge Mode Description
    •  Programmer Description
    •  Control Assembly Description

Visual/Physical Inspection
    • Inspect for aftermarket devices which could affect the operation of the HVAC System. Refer to Checking Aftermarket Accessories in Wiring Systems.
    • Inspect the easily accessible or visible system components for obvious damage or conditions which could cause the symptom.

Intermittent

Faulty electrical connections or wiring may be the cause of intermittent conditions. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.

Symptom List

Refer to a symptom diagnostic procedure from the following list in order to diagnose the symptom:

    •  HVAC Compressor Clutch Does Not Engage
    •  HVAC Compressor Clutch Does Not Disengage
    •  Blower Motor Does Not Operate Properly
    •  Cooling Insufficient - Air Conditioning (A/C) System
    •  Defrosting Insufficient
    •  Temperature Variation Between Driver and Passenger Outlets
    •  Improper Control Response
    •  Control Head Illumination/Display Does Not Operate Properly
    •  Control Head Changes by Itself
    •  Too Warm in Car
    •  Too Cool in Car
    •  Outside Air Temperature Display Inaccurate or Inoperative
    •  Set Temperature Requires Frequent Adjustment
    •  Air Delivery Improper
    •  Heating Insufficient in Heating, Ventilation and Air Conditioning
    •  Noise Diagnosis - Blower Motor in Heating, Ventilation and Air Conditioning
    •  Noise Diagnosis - Air Conditioning (A/C) System in Heating, Ventilation and Air Conditioning
    •  Odor Diagnosis in Heating, Ventilation and Air Conditioning