Remove and replace the AC pressure sensor located on the high-pressure AC line near the condenser to restore proper AC system operation and diagnostics.

Warnings

Tools required

Parts

• AC pressure sensor × 1 — Use OEM specification
• AC O-ring kit × 1 — Use OEM specification

Fluids

• R-134a refrigerant
• PAG oil

Preparation

1. Park vehicle on level surface and engage parking brake
2. Turn off engine and remove key from ignition
3. Allow engine to cool completely if recently operated
4. Verify AC pressure sensor location on high-pressure line near condenser on driver side of radiator
5. Ensure AC recovery machine is ready and functional

Procedure

1. 1

   Recover AC refrigerant
   Connect AC recovery machine to service ports on high and low pressure lines. Follow recovery machine instructions to completely evacuate all refrigerant from the system. Verify system pressure reads 0 psi on both high and low sides before proceeding.
2. 2

   Disconnect negative battery cable
   Use 10mm socket to loosen and remove negative battery terminal. Isolate cable away from battery post to prevent accidental reconnection. Wait 2 minutes for electrical system to discharge.
3. 3

   Locate AC pressure sensor
   Open hood and locate the AC pressure sensor on the high-pressure line near the condenser on the driver side. The sensor has a 2-pin electrical connector and threads directly into the AC line. On the 2015 Forte 1.8L, it is positioned between the condenser outlet and compressor inlet.
4. 4

   Disconnect electrical connector
   Press the tab on the electrical connector and pull straight away from the pressure sensor. Inspect connector terminals for corrosion or damage. Do not pull on wires.
5. 5

   Remove AC pressure sensor
   Use a 24mm wrench or appropriate socket to unthread the AC pressure sensor from the high-pressure line in a counterclockwise direction. Remove sensor completely and set aside. Inspect the sealing O-ring on the sensor for damage.
6. 6

   Prepare new sensor installation
   Install a new O-ring from the AC O-ring kit onto the new AC pressure sensor. Lightly coat the O-ring with clean PAG oil to ensure proper seal. Do not reuse the old O-ring. Inspect the threads in the AC line for damage or debris.
7. 7

   Install new AC pressure sensor
   Thread the new AC pressure sensor into the high-pressure line by hand until finger-tight. Ensure it threads smoothly without cross-threading. Tighten to 20.0 Nm (15.0 lb-ft) using a torque wrench. Do not overtighten as this can damage the line threads or crack the sensor body.
   Torque spec

   AC Line Fittings20 Nm (15 lb-ft)
8. 8

   Reconnect electrical connector
   Push the electrical connector firmly onto the new AC pressure sensor until it clicks into place. Gently tug on the connector to verify it is securely locked. Ensure no wires are pinched or damaged.
9. 9

   Reconnect battery
   Reconnect the negative battery cable and tighten securely with 10mm socket. Ensure good contact with battery post.
10. 10

    Evacuate AC system
    Connect AC vacuum pump to service ports. Evacuate system for minimum 30 minutes to remove all moisture and air. System should hold vacuum for at least 10 minutes without loss to verify no leaks at sensor.
11. 11

    Recharge AC system
    Using AC manifold gauges and charging equipment, recharge system with R-134a refrigerant to specification (typically 18-21 oz for this system). Add appropriate amount of PAG oil if required per manufacturer specifications. Monitor pressure sensor readings during charge process.

Reassembly

1. Ensure all electrical connections are secure and properly locked
2. Verify no tools or parts are left in engine compartment
3. Check for any refrigerant leaks around new sensor using leak detector

Verification

• Start engine and turn AC to maximum cold setting
• Verify AC compressor engages and cycles properly
• Check that both high and low pressure readings are within normal range (low: 25-35 psi, high: 200-250 psi at idle with ambient temp 70-80°F)
• Confirm cold air is blowing from vents with temperature around 40-50°F
• Use scan tool to verify AC pressure sensor is reporting proper values to ECM with no diagnostic trouble codes
• Inspect sensor area for any signs of refrigerant leakage (oil residue)
• Test AC operation through several on/off cycles to ensure proper system function

More procedures for this vehicle