This procedure covers the replacement of the AC high pressure switch on a 2015 Kia Forte 1.8L I4, requiring refrigerant recovery and minimal disassembly.

Warnings

Tools required

Parts

• AC high pressure switch × 1 — Use OEM specification
• O-ring seals for high pressure line × 2 — Use OEM specification
• PAG oil for AC system × 1 — Use OEM specification

Preparation

1. Ensure engine is cold before beginning work
2. Park vehicle on level surface and engage parking brake
3. Verify AC system is not pressurized by checking manifold gauges before work
4. Open hood and secure with prop rod

Procedure

1. 1

   Recover AC refrigerant
   Connect AC recovery machine to the service ports (low and high side). Follow machine instructions to fully recover all R-134a refrigerant from the system. Record the amount recovered for recharge reference. Allow system to stabilize at 0 PSI for at least 5 minutes to ensure complete recovery.
2. 2

   Locate high pressure switch
   The AC high pressure switch is located on the high pressure line near the condenser on the driver's side of the engine bay. It is a small cylindrical sensor with a two-wire electrical connector threaded into the high pressure line. Trace the high pressure line from the compressor toward the condenser to locate the switch.
3. 3

   Disconnect electrical connector
   Press the locking tab on the high pressure switch electrical connector and pull straight away from the switch. Do not pull on the wires themselves. If the connector is stuck, gently work a small flathead screwdriver under the locking tab while pulling.
4. 4

   Remove high pressure switch
   Using a 12mm wrench or appropriate socket, turn the high pressure switch counterclockwise to unthread it from the high pressure line. Remove the switch completely and inspect the sealing surface on the line for damage or debris. Wipe the area clean with a shop towel.
5. 5

   Prepare new switch
   Remove the new high pressure switch from packaging. Install new O-ring seals onto the threads of the new switch. Lightly coat the O-rings with fresh PAG oil (2-3 drops) to ensure proper sealing and prevent damage during installation. Do not over-oil.
6. 6

   Install new high pressure switch
   Thread the new high pressure switch into the high pressure line by hand, turning clockwise until finger-tight. Ensure the switch threads in smoothly without cross-threading. Using a torque wrench and 12mm socket, tighten the switch to 20.0 Nm (15.0 lb-ft) as specified for AC line fittings.
   Torque spec

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

   Reconnect electrical connector
   Push the electrical connector onto the new high pressure switch until you hear or feel a positive click, indicating the locking tab has engaged. Gently tug on the connector to verify it is fully seated and locked.
8. 8

   Evacuate and recharge AC system
   Connect the AC recovery/recharge machine to the service ports. Perform a vacuum test by pulling the system down to 29+ inches of mercury (Hg) and holding for 30 minutes to check for leaks. If vacuum holds, recharge the system with the amount of R-134a recovered earlier (typically 19-21 oz for this system). Add PAG oil if significant oil was lost during refrigerant recovery (typically 1-2 oz).

Reassembly

1. Verify all electrical connections are secure and fully seated
2. Inspect the work area for any tools or parts left behind
3. Close hood securely

Verification

• Start the engine and turn AC to MAX COOL with fan on high
• Allow system to run for 5 minutes and verify cold air is blowing from vents
• Check AC pressure readings with manifold gauges: low side should be 25-35 PSI, high side should be 200-250 PSI at idle with ambient temperature around 75-85°F
• Verify AC compressor cycles on and off properly, indicating the high pressure switch is functioning
• Inspect the high pressure switch area for any signs of refrigerant leaks (oil residue or frost)
• Confirm no unusual noises from the AC compressor or system

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