Symptoms

SYMPTOMS - HVAC SYSTEMS - AUTOMATIC

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

1. Perform the Diagnostic System Check - HVAC Systems - Automatic before using the Symptom Tables in order to verify that all of the following are true:
- There are no DTCs set.
- The control modules can communicate via the serial data link. Diagnostic System Check - HVAC System - Automatic
2. Review the system operation in order to familiarize yourself with the system functions.

Visual/Physical Inspection
- Inspect for aftermarket devices which could affect the operation of the HVAC System.
- Inspect the easily accessible or visible system components for obvious damage or conditions which could cause the symptom.
- Verify the A/C compressor clutch turns freely and is not seized.
- Verify that the customer is using the correct key to enable personalization and is not inadvertently activating auxiliary HVAC controls.
- The A/C compressor will not operate in cold outside air temperatures.
- The following conditions may cause window fogging:
- Wet carpet or mats
- High humidity
- Interior water leak
- Blocked A/C evaporator drain tube
- Maximum passenger capacity
- Blocked body pressure relief valves
- Inspect the air distribution system for causes of reduced air flow:
- Obstructed or dirty passenger compartment air filter, if equipped
- Blocked or damaged air inlet or outlet vents

Intermittent
Faulty electrical connections or wiring may be the cause of intermittent conditions.

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 Always On
- Blower Motor Inoperative
- Blower Motor Malfunction
- Too Hot in Vehicle
- Too Cold in Vehicle
- Air Delivery Improper
- Air Recirculation Malfunction
- Leak Testing 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
- Steering Wheel Controls Inoperative in Radio, Stereo and Compact Disc.