Diagnostic Table
WARNING: This page is about a different car, the 2013 Ford Escape. 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 Normal to High - Condenser - inadequate airflow.
- Engine - overheating.
Normal to High Normal - Refrigerant overcharge - air in refrigerant.
Normal to Low High - Compressor - low performance.
Normal to Low Normal to High - A/C suction line - partially restricted or plugged.(1)
Normal to Low Low or Clutch Cycling - Low refrigerant charge - leak in system.
- A/C suction line - partially restricted or plugged.(2)
Erratic Operation or Compressor Not Running - AAT sensor - poor connection.
- A/C pressure transducer - poor connection.
- Evaporator temperature sensor - poor connection.
- Low refrigerant charge - leak in system.
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
(1) Low pressure reading will be normal to high if restriction is downstream of service access valve. (2) Low pressure reading will be low restriction is upstream of service access valve.