This procedure covers the removal and replacement of the Idle Air Control Valve (IACV) on the 2015 Kia Forte 1.8L I4 engine to restore proper idle control and engine performance.

Warnings

Tools required

Parts

• Idle Air Control Valve × 1 — Use OEM specification
• IAC valve gasket × 1 — Use OEM specification
• Throttle body cleaner × 1 — Any quality throttle body cleaner

Preparation

1. Park vehicle on level ground and engage parking brake.
2. Allow engine to cool completely (minimum 30 minutes after running).
3. Disconnect negative battery terminal and wait 5 minutes for system capacitors to discharge.
4. Remove engine cover by pulling upward on pull tabs (no tools required).
5. Locate the throttle body on the intake manifold; the IAC valve is mounted on the side or rear of the throttle body.

Procedure

1. 1

   Access the IAC valve
   Remove any air intake components obstructing access to the throttle body. Loosen the clamp on the air intake tube at the throttle body and disconnect the tube. Move it aside to provide clear access to the IAC valve mounted on the throttle body assembly.
2. 2

   Disconnect IAC valve electrical connector
   Locate the electrical connector attached to the IAC valve. Press the release tab on the connector and pull straight out to disconnect. Inspect the connector terminals for corrosion or damage; clean with electrical contact cleaner if needed.
3. 3

   Remove IAC valve mounting screws
   Using a 10mm socket or appropriate screwdriver, carefully remove the two mounting screws securing the IAC valve to the throttle body. Keep screws in a safe location for reinstallation. Note the exact orientation of the valve before removal.
   Torque spec

   IAC Valve Screws3 Nm (2 lb-ft)
4. 4

   Remove IAC valve from throttle body
   Gently pull the IAC valve straight out from the throttle body. The valve may require slight wiggling to break the gasket seal. Do not pry against the throttle body bore. Remove and discard the old gasket from the mating surface.
   ⚠Do not allow the IAC valve pintle to strike hard surfaces as this can damage the valve mechanism.
5. 5

   Clean mating surfaces
   Using a plastic gasket scraper and shop towels, carefully clean all gasket material from the throttle body mating surface. Ensure no debris falls into the throttle body bore. Spray throttle body cleaner on a towel and wipe the IAC valve mounting area clean. Allow to dry completely.
6. 6

   Inspect throttle body bore
   With the IAC valve removed, inspect the throttle body bore and idle air passage for carbon buildup. If excessive deposits are present, clean with throttle body cleaner and a soft cloth. Do not spray cleaner directly into electronic components.
7. 7

   Install new IAC valve gasket
   Position the new IAC valve gasket onto the throttle body mating surface, ensuring proper alignment with the screw holes and air passage. The gasket should sit flat without wrinkles or gaps.
8. 8

   Install new IAC valve
   Carefully insert the new IAC valve into the throttle body, aligning the valve pintle with the air passage opening. Ensure the gasket remains properly seated. Push the valve in until it sits flush against the gasket and mounting surface.
9. 9

   Secure IAC valve mounting screws
   Install the two mounting screws by hand, threading them carefully to avoid cross-threading. Once both screws are hand-tight, use a torque wrench to tighten them to specification in a cross pattern. Do not overtighten as this can damage the valve body or strip the aluminum threads.
   ⚠These screws require very low torque (3.0 Nm). Overtightening will crack the IAC valve housing or strip threads.
   Torque spec

   IAC Valve Screws3 Nm (2 lb-ft)
10. 10

    Reconnect electrical connector
    Push the electrical connector firmly onto the IAC valve until it clicks into place. Gently tug on the connector to verify it is fully seated and locked.
11. 11

    Reinstall air intake components
    Reconnect the air intake tube to the throttle body and tighten the clamp securely. Ensure all vacuum lines and connections disturbed during removal are properly reconnected.
12. 12

    Reconnect battery and initialize system
    Reconnect the negative battery terminal. Turn the ignition to ON position (do not start engine) for 10 seconds, then turn OFF. Repeat this cycle 3 times to allow the ECU to recognize the new IAC valve and initialize baseline settings.

Reassembly

1. Reinstall engine cover by aligning clips and pressing down until seated.
2. Double-check all electrical connections are secure and no tools were left in the engine bay.
3. Reset power windows by holding the auto-down button for 5 seconds, then auto-up for 5 seconds on each window if necessary.

Verification

• Start the engine and allow it to idle. Initial idle may be rough for 30-60 seconds while the ECU relearns idle parameters.
• Verify idle speed stabilizes between 650-750 RPM when fully warmed up with no accessories running.
• Turn on electrical loads (headlights, A/C, rear defrost) and verify idle compensates appropriately without stalling.
• Check for vacuum leaks around the IAC valve by listening for hissing sounds.
• Use a scan tool to verify no IAC-related trouble codes are present and that IAC valve command values respond properly.
• Test drive the vehicle and verify smooth transitions from deceleration to idle with no stalling or surging.

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