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Procedure 3 - Ambient Temperature Above 38 °C (100 °F)

WARNING: This page is about a different car, the 2017 Lincoln Navigator and 2017 Ford Expedition. However, it is still accessible from the selected car via links, so may be relevant.

  1. 1.

    Run the engine until it reaches normal operating temperature.

  1. 2.

    Connect the air conditioning service unit to the refrigerant system.

  1. 3.

    Set the Air Conditioning (A/C) system temperature to the lowest possible temperature setting with the dual function disabled (if equipped). Manually set the blower on HI. If the vehicle has a fresh air/recirc button, set it to FRESH. If the vehicle has an A/C switch or compressor on switch, set it to A/C ON.

  1. 4.

    Open all vehicle windows and leave the hood open for the test. Open the rear hatch and/or rear doors (if equipped).

  1. 5.

    Confirm the compressor is operating and the engine cooling fan(s) are operating or engaged. Allow the vehicle to idle until the suction (low-side) and discharge (high-side) pressures are stable or fluctuate in a range that repeats.

  1. 6.

    Record the ambient (shop) temperature.

  1. 7.

    Record the discharge pressure. If the pressure is fluctuating, record the average value.

  1. 8.

    Determine if the discharge pressure falls within the normal operating limits using the Normal Refrigerant Discharge Pressures chart.
GFD136694Courtesy of FORD MOTOR COMPANY

  1. 9.

    Record the suction pressure. If the pressure is fluctuating, record the average value.

  1. 10.

    Determine if the suction pressure falls between normal operating limits using the Normal Refrigerant Suction Pressures chart.
GFD136695Courtesy of FORD MOTOR COMPANY

  1. 11.

    Proceed to the diagnostic table.