hvac
AC High Pressure Switch
for 2015 Kia Forte 1.8L I4 · FWD
Editorial review:Chris Hackleman — Master Technician · 20+ years · Jeff Moore — Master Mechanic · 20+ years
Difficulty
Easy
Time
30 min
Tools
8
Steps
8
✓Expert-verified. Personally reviewed and approved by OLP's master technicians (Chris Hackleman & Jeff Moore — 20+ years each). Always follow the vehicle's factory service information and torque specs.
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
⚠️AC refrigerant must be recovered by certified equipment before disconnecting any AC lines. Venting refrigerant is illegal and environmentally harmful.
⚠Residual refrigerant pressure may remain in the system even after recovery. Release pressure slowly when disconnecting fittings.
⚠PAG oil and refrigerant can cause skin and eye irritation. Wear protective equipment.
Tools required
R-134a AC recovery/recharge machineEssential
Torque wrench (10-30 Nm range)Essential
10mm socket and ratchetEssential
Safety glassesEssential
Nitrile glovesEssential
As an Amazon Associate and Autel/ANCEL partner, OLP earns from qualifying purchases — how we link. This never changes the specs we publish.
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
As an Amazon Associate and Autel/ANCEL partner, OLP earns from qualifying purchases — how we link. This never changes the specs we publish.
Preparation
- Ensure engine is cold before beginning work
- Park vehicle on level surface and engage parking brake
- Verify AC system is not pressurized by checking manifold gauges before work
- Open hood and secure with prop rod
Procedure
- 1Recover AC refrigerantConnect 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.
- 2Locate high pressure switchThe 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.
- 3Disconnect electrical connectorPress 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.
- 4Remove high pressure switchUsing 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.
- 5Prepare new switchRemove 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.
- 6Install new high pressure switchThread 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 specAC Line Fittings20 Nm (15 lb-ft)
- 7Reconnect electrical connectorPush 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.
- 8Evacuate and recharge AC systemConnect 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
- Verify all electrical connections are secure and fully seated
- Inspect the work area for any tools or parts left behind
- 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
Related trouble codes on this vehicle
Codes that commonly send this job to the bay — tap one for symptoms, causes, and diagnostic steps.
P0087Fuel Rail/System Pressure - Too LowP0088Fuel Rail/System Pressure - Too HighP0090Fuel Pressure Regulator 1 Control CircuitP0091Fuel Pressure Regulator 1 Control Circuit LowP0105Manifold Absolute Pressure/BARO CircuitP0106MAP/BARO Pressure Circuit Range/PerformanceP0190Fuel Rail Pressure Sensor CircuitP0191Fuel Rail Pressure Sensor Circuit Range/PerformanceP0452EVAP Pressure Sensor/Switch Low InputP0453EVAP Pressure Sensor/Switch High InputP0520Engine Oil Pressure Sensor/Switch CircuitP0521Engine Oil Pressure Sensor/Switch Range/Performance
Chasing one of these codes and not sure which part is guilty? Ask a master mechanic about YOUR car →