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. |
| • | Verify that the customer is using the correct key to enable personalization
and is not inadvertently activating passenger HVAC controls. |
| • | 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
in Wiring Systems.
Symptom List
Refer to a symptom diagnostic procedure from the following list in order
to diagnose the symptom:
