Symptoms

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

1. Perform Diagnostic System Check - HVAC Systems - Automatic before using the Symptom Tables in order to verify that all of the following are true:
^ No DTCs are 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 procedures:
^ Air Delivery Description and Operation
^ Air Temperature Description and Operation

Visual/Physical Inspection
^ Inspect for aftermarket devices which could affect the operation of the HVAC System. Refer to Checking Aftermarket Accessories in Diagrams.
^ 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 steering wheel or passenger HVAC controls, if equipped.
^ The A/C compressor will not operate in cold ambient air temperatures. Refer to Air Temperature Description and Operation.
^ 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. Refer to Testing for Intermittent and Poor Connections in Diagrams.

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
^ Temperature Variation Between Driver and Passenger Outlets
^ Control Head Illumination/Display Does Not Operate Properly
^ Too Hot in Vehicle
^ Too Cold in Vehicle
^ Outside Air Temperature Display Inaccurate
^ Steering Wheel Controls Inoperative
^ Passenger HVAC Control Does Not Operate Properly
^ Air Delivery Improper
^ A/C System Does Not Maintain Set Temperature
^ Air Recirculation Malfunction
^ Afterblow Enable Procedure
^ Leak Testing in Heating, Ventilation, and Air Conditioning Leak Testing
^ Noise Diagnosis - Blower Motor in Heating, Ventilation, and Air Conditioning Noise Diagnosis - Blower Motor
^ Noise Diagnosis - A/C System in Heating, Ventilation, and Air Conditioning Noise Diagnosis - A/C System
^ Odor Diagnosis in Heating, Ventilation, and Air Conditioning Odor Diagnosis
^ Improper Control Response
^ Control Head Changes by Itself
^ Set Temperature Requires Frequent Adjustment
^ Dual-Stage Orifice Malfunction
^ Heating Performance Diagnostic in Heating, Ventilation, and Air Conditioning Heating Performance Diagnostic