A/C Diagnostics Chart
WARNING: This page is about a different car, the 2022 Cadillac CT4. However, it is still accessible from the selected car via links, so may be relevant.
| A/C System Concern | Potential Causes | |
|---|---|---|
| Compressor Inoperative | Electrical Wiring Issue | |
| No or Low Refrigerant Charge (Greater than -.07 kg / - 0.154 lbs) |
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| Compressor Internal Malfunction | ||
| Compressor Clutch Malfunction | ||
| A/C Pressure Sensor Malfunction | ||
| Evaporator Air Temperature (EAT) Malfunction | ||
| HVAC Controls Malfunction | ||
| Low Side Gauge Reading | High Side Gauge Reading | Potential Causes |
| Same as High Side | Same as Low Side | No or Low Refrigerant Charge (Greater than -.07 kg / - 0.154 lbs) |
| Compressor Malfunction | ||
| A/C Pressure Sensor Malfunction | ||
| EAT Malfunction | ||
| HVAC Controls Malfunction | ||
| Normal | Normal | Temperature Actuator Malfunction |
| Temperature Door Malfunction | ||
| Low | Low | Low Refrigerant Charge (Greater than -.07 kg / - 0.154 lbs) |
| Restriction between the Compressor Outlet and Low Side Port | ||
| Low/Normal | Evaporator Freezing/EAT Malfunction | |
| High | Compressor Stuck at Maximum Displacement/EAT Malfunction | |
| Normal/High | Normal/High | Air Conditioning Oil Overcharge |
| High | Low | Restriction between the Low Side Port and Compressor Inlet |
| Expansion Device Stuck Open | ||
| Compressor has Low Displacement or Internal Malfunction | ||
| High | Malfunctioning Cooling Fans | |
| Refrigerant Overcharge (Greater than +.03 kg /+ 0.066 lbs) |
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| Restricted Condenser Air Flow | ||
| Air in A/C System | ||
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NOTE:
Restrictions can occur in any part of an A/C system and may result in various gauge pressure values, depending on the system design and service port locations. The use of a non-contact, infrared thermometer can help diagnose a restricted A/C system with the ability to quickly observe significant, unexpected temperature changes in components and plumbing due to debris, contamination, pinched/damaged hoses, etc.
NOTE:
This vehicle has a refrigerant charge operational tolerance of -.07 kg to +.03 kg / - 0.154 lbs to + 0.066 lbs. If refrigerant charge falls outside of this range, please refer to Air Conditioning (A/C) System Performance Test. |
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