Important: The following steps must be completed before using the symptom tables.
- Perform the 
Diagnostic System Check - HVAC Systems - Automatic 
 before using the Symptom Tables in
order to verify that all of the following are true:
 
| •  | The control module(s) can communicate via the serial data link. | 
 
- Review the system operation in order to familiarize yourself with
the system functions. Refer to
 
Visual/Physical Inspection
|     •  | 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. | 
 
|     •  | The following could cause window fogging: | 
 
|        -  | 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 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: