Symptoms - HVAC Systems - Automatic
| Symptoms - HVAC Systems - Automatic |
| Note | ||
|
The following steps must be completed before using the symptom tables: |
| 1. |
Perform the
Diagnostic System Check - Vehicle
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.
|
| 2. |
Review the system operation in order to familiarize yourself with the system functions. Refer to
Automatic HVAC Description and Operation
.
|
|
| Visual/Physical Inspection |
| • |
Inspect for aftermarket devices which may affect the operation of the HVAC System. Refer to
Checking Aftermarket Accessories
.
|
|
| • |
Inspect the easily accessible or visible system components for obvious damage or conditions which could cause the symptom.
|
|
| • |
Verify the A/C compressor 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. 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:
| • |
Air Conditioning Compressor Malfunction (LAU, LBR, LBS, LDK, or LHU)
Air Conditioning Compressor Malfunction (LLU)
|
|
| • |
Blower Motor Malfunction
|
|
| • |
Air Temperature Malfunction
|
|
| • |
Air Delivery Improper
|
|
| • |
Air Recirculation Malfunction
|
|
| • |
Auxiliary Blower Motor Malfunction
|
|
| • |
Auxiliary Air Temperature Malfunction
|
|
| • |
Air Delivery Improper - Auxiliary
|
|
