This procedure covers the removal and replacement of the Idle Air Control Valve on the 2016-2024 Hyundai Tucson 2.5L 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/O-ring × 1 — Use OEM specification
• Throttle body gasket (if damaged) × 1 — Use OEM specification

Preparation

1. Ensure engine is completely cool to the touch
2. Disconnect negative battery terminal and wait 3 minutes for system discharge
3. Remove engine cover by lifting firmly at front clips and pulling rearward
4. Have replacement gasket or O-ring ready before removal to minimize open time

Procedure

1. 1

   Access the IAC valve location
   Locate the IAC valve on the throttle body assembly, positioned on the driver's side of the intake manifold. Remove any air ducting or intake hose that obstructs access by loosening hose clamps and disconnecting breather tubes. On AWD models, you may need to move aside wiring harnesses secured to the intake.
2. 2

   Disconnect electrical connector
   Press down on the locking tab of the IAC valve electrical connector while pulling straight away from the valve. Do not twist or rock the connector excessively. If connector is stuck, use a small flathead screwdriver to carefully depress the tab while pulling.
   ⚠Connector locking tabs are fragile plastic and cannot be replaced separately from the wiring harness.
3. 3

   Remove IAC valve mounting screws
   Remove the two mounting screws securing the IAC valve to the throttle body using a 10mm socket. Keep screws organized as they may have specific length requirements for reinstallation. Gently wiggle the valve to break the gasket seal.
4. 4

   Extract the IAC valve
   Carefully pull the IAC valve straight out from the throttle body. If resistance is felt, gently rotate while pulling to avoid damaging the bore. Note the orientation of the valve and any alignment pins for proper reinstallation.
5. 5

   Inspect and clean mating surfaces
   Remove and discard the old gasket or O-ring. Inspect the throttle body bore for carbon buildup, scoring, or damage. Use a soft wire brush and parts cleaner to remove carbon deposits from the mounting surface and bore. Wipe clean with shop towels and ensure no debris falls into the intake manifold.
   ⚠Do not allow cleaning solvent or debris to enter the intake manifold or throttle body passages.
6. 6

   Prepare new IAC valve
   Install the new gasket or O-ring onto the replacement IAC valve. Lightly lubricate the O-ring with clean engine oil if specified by the replacement part instructions. Verify the pintle extends and retracts freely by hand if it is a stepper motor type.
7. 7

   Install new IAC valve
   Align the IAC valve with any locating pins or tabs on the throttle body. Insert the valve straight into the bore without rotating. Ensure the gasket seats evenly against the throttle body surface before installing screws.
8. 8

   Secure IAC valve
   Install the two mounting screws and tighten in a cross pattern to the specified torque using a torque wrench. Start with finger-tight, then torque to specification. Do not overtighten as this can crack the valve housing or strip the aluminum throttle body threads.
   ⚠Exceeding 3.0 Nm torque specification can damage the valve housing or throttle body threads.
   Torque spec

   IAC Valve Screws3 Nm (2 lb-ft)
9. 9

   Reconnect electrical connector
   Push the electrical connector straight onto the IAC valve until you hear and feel a positive click. Gently tug on the connector to verify it is fully locked. Ensure no wires are pinched or under tension.
10. 10

    Reinstall intake components
    Reinstall any air ducting, intake hoses, and wiring harnesses removed during access. Ensure all hose clamps are properly tightened and breather tubes are fully seated. Replace engine cover by aligning rear tabs first, then pressing down firmly at front clips until they click.

Reassembly

1. Reconnect the negative battery terminal and tighten securely
2. Do not start engine immediately; proceed to verification steps first
3. Ensure all tools and materials are removed from engine bay

Verification

• Turn ignition to ON position (without starting) for 10 seconds, then OFF. Repeat this cycle 3 times to allow the ECU to initialize the new IAC valve position
• Start the engine and allow it to idle for 2-3 minutes. Idle may be rough initially as the system relearns
• Verify idle speed stabilizes between 600-800 RPM when fully warmed
• With engine at idle, turn on accessories (A/C, headlights, rear defrost) and verify idle compensation occurs without stalling
• Check for vacuum leaks around the IAC valve by listening for hissing sounds
• If available, use an OBD-II scanner to verify no IAC-related fault codes are present
• Road test the vehicle and verify smooth idle at stop lights and no stalling during deceleration

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