AC Pressure Sensor

This procedure covers the replacement of the AC pressure sensor on the 2015-2020 Ford F-150 with 3.5L EcoBoost engine, which monitors refrigerant pressure for proper AC system operation.

Warnings

Tools required

Parts

• AC pressure sensor × 1 — Use OEM specification
• AC line O-rings × 2 — Use OEM specification

Fluids

• R-134a refrigerant
• PAG 46 oil

Preparation

1. Park vehicle on level surface and engage parking brake
2. Allow engine to cool completely if recently operated
3. Have AC system professionally evacuated and refrigerant recovered
4. Verify replacement sensor matches original part number
5. Open hood and secure in upright position

Procedure

1. 1

   Locate AC pressure sensor
   The AC pressure sensor is located on the high-pressure AC line near the condenser on the passenger side of the engine bay. It is a small cylindrical sensor with an electrical connector and threaded into the AC line.
2. 2

   Disconnect electrical connector
   Press the tab on the electrical connector and carefully pull it away from the AC pressure sensor. Do not pull on the wiring harness itself, only the connector body.
3. 3

   Remove AC pressure sensor
   Using a 10mm socket, carefully unthread the AC pressure sensor from the high-pressure line. Turn counterclockwise to remove. Be prepared for a small amount of residual oil to leak out. Have a shop towel ready to catch any drips.
4. 4

   Inspect and clean sensor port
   Inspect the sensor port threads for damage or debris. Clean the port opening with a clean shop towel. Check the condition of the O-ring sealing surface and remove the old O-ring if still in place.
5. 5

   Install new O-rings
   Install new O-rings onto the replacement AC pressure sensor. Lightly coat the O-rings with fresh PAG oil to ensure proper sealing and ease of installation. Do not use excessive oil.
6. 6

   Install new AC pressure sensor
   Thread the new AC pressure sensor into the high-pressure line by hand, turning clockwise until finger-tight. Ensure the sensor threads in smoothly without cross-threading. Then use a 10mm socket and torque wrench to tighten to specification.
   Torque spec

   AC Line Fittings20 Nm (15 lb-ft)
7. 7

   Reconnect electrical connector
   Push the electrical connector onto the new AC pressure sensor until you hear and feel a positive click. Gently tug on the connector to verify it is fully seated and locked in place.
8. 8

   Recharge AC system
   Have the AC system professionally evacuated to remove air and moisture, then recharged to the proper refrigerant capacity specification using AC recovery/recharge equipment. The system should be evacuated for at least 30 minutes before recharging.

Reassembly

1. Verify all electrical connections are secure and properly seated
2. Ensure no tools or materials are left in engine bay
3. Close hood securely

Verification

• Start engine and turn AC system to maximum cooling
• Verify AC compressor engages and system operates normally
• Check for any refrigerant leaks around the new sensor using leak detector or soap solution
• Monitor AC system pressure readings using scan tool to confirm sensor is reporting accurate values
• Verify cold air is blowing from vents and system pressure is within normal range (typically 200-250 PSI on high side at idle)
• Test AC operation for at least 10 minutes to ensure stable performance

Related trouble codes on this vehicle

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