Inspection
NOTE: Procedure 1 — Ambient Temperature below 21 °C (70 °F).
NOTE: Proper A/C system diagnosis on a vehicle’s compressor is dependent on correct refrigerant system charge and tested in ambient temperatures above 21°C (70°F). Perform the following steps to achieve normal operating pressures.
Drive the vehicle or run the engine until it reaches normal operating temperature.Inspection
NOTE: Procedure 2 — Ambient Temperature between 21 °C (70 °F) and 38 °C (100 °F)
Run the engine until it reaches normal operating temperature.![]() |
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NOTE: Use the following table to guide diagnosis of the refrigerant system if operating pressures are outside normal limits.
NOTE: Proper A/C system diagnosis on vehicles with Electric Compressors is dependent on correct refrigerant system charge and tested in ambient temperatures above 21°C (70°F). Never replace an Electric Compressor without first recovering and recharging the A/C system to vehicle specification and retesting in ambient temperatures above 21°C (70°F).
| High (Discharge) Pressure | Low (Suction) Pressure | Component — Causes |
|---|---|---|
| High | Normal to High |
|
| Normal to High | Normal |
|
| Normal to Low | High |
|
| Normal to Low | Normal to High |
|
| Normal to Low | Low |
|
| Normal to High | Low |
|
| Normal to High | High |
|
| Normal to High | Low |
|
| Normal to Low | Normal to Low |
|
| Normal to High | Low |
|
| Normal to Low | Low |
|
| High | Low |
|
| Erratic Operation or Compressor Not Running |
|
|
| Additional Possible Components or Causes Associated With Inadequate Compressor Operation |
|
|
a Low pressure reading will be normal to high if restriction is downstream of service access valve.
b Low pressure reading will be low if restriction is upstream of service access valve.
Inspection
NOTE: Procedure 3 — Ambient Temperature Above 38 °C (100 °F)
Run the engine until it reaches normal operating temperature.![]() |
![]() |
NOTE: Use the following table to guide diagnosis of the refrigerant system if operating pressures are outside normal limits.
NOTE: Proper A/C system diagnosis on vehicles with Electric Compressors is dependent on correct refrigerant system charge and tested in ambient temperatures above 21°C (70°F). Never replace an Electric Compressor without first recovering and recharging the A/C system to vehicle specification and retesting in ambient temperatures above 21°C (70°F).
| High (Discharge) Pressure | Low (Suction) Pressure | Component — Causes |
|---|---|---|
| High | Normal to High |
|
| Normal to High | Normal |
|
| Normal to Low | High |
|
| Normal to Low | Normal to High |
|
| Normal to Low | Low |
|
| Normal to High | Low |
|
| Normal to High | High |
|
| Normal to High | Low |
|
| Normal to Low | Normal to Low |
|
| Normal to High | Low |
|
| Normal to Low | Low |
|
| High | Low |
|
| Erratic Operation or Compressor Not Running |
|
|
| Additional Possible Components or Causes Associated With Inadequate Compressor Operation |
|
|
a Low pressure reading will be normal to high if restriction is downstream of service access valve.
b Low pressure reading will be low if restriction is upstream of service access valve.
General Procedures - Refrigerant System Tests - 2.0L EcoBoost (177kW/240PS) – MI4
General Procedures - Reset the Outside Air Temperature Sensor Learned ValuesLocating the Vehicle Identification Number
The vehicle identification number is on the left-hand side of the instrument panel.
