Important: The following steps must be completed before using the symptom tables:
- Perform the
Diagnostic System Check - Vehicle
before using the Symptom Tables in order to verify that all of the following are true:
| • | The control modules can communicate via the serial data link. |
- Review the system operation in order to familiarize yourself with the system functions. Refer to
Automatic HVAC Description and Operation
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. |
| • | 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: |
| - | 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
.
Symptom List
Refer to a symptom diagnostic procedure from the following list in order to diagnose the symptom:
