Symptom Chart -- Climate Control Systems
| Condition | Possible Sources | Action |
|---|---|---|
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NOTE:
Some PCM DTCs may inhibit A/C operation. If any PCM DTCs are retrieved, diagnose those first. Refer to ENGINE CONTROLS - INTRODUCTION (EXCEPT DIESEL & HYBRID)
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| No communication with the HVAC control module | Fuse Wiring, terminals or connectors Communication network HVAC control module |
REFER to Module Communications Network . |
| Externally Controlled Variable Displacement Compressor (EVDC) poor performance/does not operate correctly | Refer to the Pinpoint Test | GO to Pinpoint Test Z . |
| Unable to duplicate the customer concern and no DTCs present | Refer to the Pinpoint Test | GO to Pinpoint Test H . |
| The HVAC functions are inoperative/do not operate correctly from touchscreen only | Communication network FCDIM |
REFER to Information and Entertainment Systems - 4.2-Inch (107 mm) Screen, 4 Or 6 Speakers or Information And Entertainment System - 8-Inch (203 Mm) Touchscreen, 7 Speakers Symptom Chart and DIAGNOSE the touchscreen. |
| The air inlet door is inoperative | Refer to the Pinpoint Test | GO to Pinpoint Test I . |
| Incorrect/erratic direction of airflow from outlets | Refer to the Pinpoint Test | GO to Pinpoint Test J . |
| Reduced outlet airflow | Refer to the Pinpoint Test | If the A/C compressor does not cycle, GO to Pinpoint Test M . If the A/C compressor cycles normally, GO to Pinpoint Test R . |
| Insufficient, erratic or no heat | Refer to the Pinpoint Test | GO to Pinpoint Test K . |
| The A/C is inoperative | Refer to the Pinpoint Test | GO to Pinpoint Test L . |
| The A/C operation is erratic. The discharge air warms up when the vehicle comes to a stop. | Refer to the Pinpoint Test | DIAGNOSE all PCM DTCs before proceeding. REFER to the PCM DTC Chart If no PCM DTCs are present GO to Pinpoint Test X . |
| The A/C is always on -- A/C compressor does not cycle | Refer to the Pinpoint Test | GO to Pinpoint Test M . |
| The A/C is always on -- A/C mode always commanded ON | Refer to the Pinpoint Test | GO to Pinpoint Test N . |
| Temperature control is inoperative/does not operate correctly | Refer to the Pinpoint Test | For driver side temperature concern, GO to Pinpoint Test O . For passenger side temperature concern, GO to Pinpoint Test P . |
| The blower motor is inoperative | Refer to the Pinpoint Test | GO to Pinpoint Test Q . |
| The blower motor does not operate correctly | Refer to the Pinpoint Test | GO to Pinpoint Test R . |
| A/C pressure relief valve discharging | High system pressure A/C pressure relief valve |
CHECK the high side system pressure. If the pressure is below the A/C pressure relief valve open pressure, INSTALL a new A/C compressor. REFER to Climate Control . If the system pressure is above the A/C pressure relief valve open pressure, REPAIR the system for a restriction. |