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 | |

 
		