Diagnostic Table
WARNING: This page is about a different car, the 2014 Ford F-150. However, it is still accessible from the selected car via links, so may be relevant.
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NOTE:
The following table is used to guide diagnosis of the refrigerant system if operating pressures are outside normal limits.
Refer to the chart below.
| High (Discharge) Pressure |
Low (Suction) Pressure |
Component - Causes |
| High or Clutch Cycling |
High |
Condenser - inadequate airflow. |
| High |
Normal to High |
Engine - overheating. |
| Normal to High |
Normal |
Refrigerant overcharge - air in refrigerant. |
| Normal to Low |
High |
TXV
not operating correctly. |
| Normal to Low |
Normal to High |
A/C suction line - partially restricted or plugged. |
| Normal to Low |
Low or Clutch Cycling |
Low refrigerant charge, A/C suction line - partially restricted or plugged A/C cycling switch - sticking closed (if equipped). |
| Erratic Operation or Compressor Not Running |
A/C cycling switch - poor connection at A/C clutch connector or clutch cycling switch connector. A/C electrical circuit erratic - see A/C Electrical Circuit Wiring Diagram. |
| Normal to Low |
High |
Compressor - low performance. |
| Additional Possible Cause Components Associated With Inadequate Compressor Operation |
- Compressor Drive Belt - loose
- Compressor Clutch - slipping
- Clutch Coil Open - shorted, or loose mounting
- Control Assembly Switch - dirty contacts or sticking open
- Clutch Wiring Circuit - high resistance, open or blown fuse
- Compressor Operation Interrupted by Engine Computer
|
| Additional Possible Cause Components Associated With a Damaged Compressor |
- Incorrect Clutch Air-gap
- Suction Accumulator - refrigerant oil bleed hose plugged
- Refrigerant Leaks
|