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:
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There are no DTCs set.
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The control modules can communicate via the serial data link.
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2. |
Review the system operation in order to familiarize yourself with the system functions. Refer to
Automatic HVAC Description and Operation
.
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Visual/Physical Inspection |
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Inspect for aftermarket devices which may affect the operation of the HVAC System. Refer to
Checking Aftermarket Accessories
.
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Inspect the easily accessible or visible system components for obvious damage or conditions which could cause the symptom.
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Verify the A/C compressor turns freely and is not seized.
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Verify that the customer is using the correct key to enable personalization and is not inadvertently activating auxiliary HVAC controls.
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The A/C compressor will not operate in cold outside air temperatures.
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The following conditions may cause window fogging:
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Wet carpet or mats
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High humidity
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Interior water leak
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Blocked A/C evaporator drain tube
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Maximum passenger capacity
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Blocked body pressure relief valves
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Inspect the air distribution system for causes of reduced air flow:
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Obstructed or dirty passenger compartment air filter, if equipped
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Blocked or damaged air inlet or outlet vents
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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:
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Air Conditioning Compressor Malfunction (LAU, LBR, LBS, LDK, or LHU)
Air Conditioning Compressor Malfunction (LLU)
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Blower Motor Malfunction
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Air Temperature Malfunction
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Air Delivery Improper
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Air Recirculation Malfunction
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Auxiliary Blower Motor Malfunction
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Auxiliary Air Temperature Malfunction
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Air Delivery Improper - Auxiliary
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