- Symptoms - HVAC Systems - Manual

SYMPTOMS

IMPORTANT: 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 module(s) can communicate via the serial data link. Testing and Inspection
2. Review the system operation in order to familiarize yourself with the system functions. Refer to Air Delivery Description and Operation

Visual/Physical Inspection
1. Inspect for aftermarket devices which could affect the operation of the HVAC System.
2. Inspect the easily accessible or visible system components for obvious damage or conditions which could cause the symptom.
3. Verify the A/C compressor clutch turns freely and is not seized.
4. Verify that the customer is using the correct key to enable personalization and is not inadvertently activating auxiliary HVAC controls.
5. 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
6. 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. Component Tests and General Diagnostics

Symptom List

Discharge High Pressure Abnormally High:

Discharge Pressure Abnormally Low:

Suction Low Pressure Abnormally Low:

Suction Pressure Abnormally High:

Suction And Discharge Pressure Abnormally High Charge:

Suction And Discharge Pressure Abnormally Low:

Refrigerant Leaks:

Low And High Side Pressure Relationship Chart:

Refer to a symptom diagnostic procedure from the following list in order to diagnose the symptom:
- HVAC Compressor Clutch Does Not Engage Compressor Clutch Does Not Engage
- Blower Motor Malfunction Blower Motor Malfunction
- Too Hot in Vehicle Too Hot In Vehicle
- Too Cold in Vehicle Too Cold in Vehicle
- Air Delivery Improper Air Delivery Improper
- Improper Control Response Improper Control Response