Idle Air Control Valve

This procedure covers the removal and replacement of the Idle Air Control Valve on the 2014-2018 Chevrolet Silverado 1500 with the 5.3L V8 EcoTec3 L83 engine.

Warnings

Tools required

Parts

• Idle Air Control Valve × 1 — AC Delco 217-3108 or OEM equivalent
• IAC valve gasket or O-ring × 1 — Use OEM specification

Preparation

1. Park vehicle on level surface and engage parking brake
2. Allow engine to cool completely for at least 30 minutes
3. Disconnect negative battery cable to prevent electrical issues
4. Verify you have the correct replacement part, as the L83 engine uses an integrated throttle body system

Procedure

1. 1

   Access the throttle body assembly
   Remove the engine cover by pulling upward on the front edge, then lifting up to release the retaining grommets. Set the cover aside in a clean area.
2. 2

   Disconnect the air intake duct
   Loosen the hose clamp at the throttle body connection using a flathead screwdriver or socket. Disconnect any breather hoses or PCV connections from the intake duct. Remove the air intake duct from the throttle body and set aside.
3. 3

   Disconnect throttle body electrical connector
   Locate the electrical connector on the throttle body assembly. Press the release tab and carefully disconnect the harness connector. Do not pull on the wires themselves.
4. 4

   Remove throttle body mounting bolts
   Remove the four throttle body mounting bolts securing the throttle body to the intake manifold. Keep bolts organized for reinstallation.
   Torque spec

   Mounting Bolts60 Nm (44 lb-ft)
5. 5

   Remove throttle body assembly
   Carefully lift the throttle body assembly away from the intake manifold. The gasket may stick to either surface. Inspect the old gasket and remove it completely from both mating surfaces.
6. 6

   Clean mating surfaces
   Use a clean rag and throttle body cleaner to thoroughly clean both the intake manifold and throttle body mating surfaces. Remove all old gasket material and debris. Ensure surfaces are completely dry before proceeding.
   ⚠Do not allow debris or cleaning solution to enter the intake manifold opening
   Torque spec

   Gasket Surface Bolts26 Nm (19 lb-ft)
7. 7

   Install new gasket
   Position the new throttle body gasket onto the intake manifold surface, ensuring proper alignment with all bolt holes and the air passage opening.
8. 8

   Install throttle body assembly
   Carefully position the throttle body assembly onto the new gasket, aligning all mounting bolt holes. Install the four mounting bolts finger-tight initially.
9. 9

   Torque mounting bolts
   Using a torque wrench, tighten the throttle body mounting bolts in a criss-cross pattern to 60.0 Nm (44.0 lb-ft). Start with the upper bolts, then proceed to the lower bolts, alternating to ensure even seating.
   Torque spec

   Mounting Bolts60 Nm (44 lb-ft)
10. 10

    Reconnect electrical connector
    Reconnect the throttle body electrical connector, ensuring it clicks securely into place. Verify the connector lock is fully engaged.
11. 11

    Reinstall air intake duct
    Position the air intake duct onto the throttle body. Tighten the hose clamp securely. Reconnect any breather hoses or PCV connections to the intake duct.
12. 12

    Reinstall engine cover
    Align the engine cover mounting grommets with the studs on the engine. Press down firmly until all grommets are fully seated.

Reassembly

1. Reconnect the negative battery cable
2. The throttle body may require a relearn procedure after installation
3. Start the engine and allow it to idle; the PCM will perform an automatic idle relearn

Verification

• Turn ignition to ON position without starting engine and verify no check engine light for throttle body codes
• Start the engine and verify smooth idle operation without stumbling or stalling
• Check for any vacuum leaks around the throttle body gasket
• Test drive vehicle and verify normal throttle response and idle quality when coming to a stop
• If idle issues persist, perform a throttle body relearn procedure using a scan tool per GM service procedures

Related trouble codes on this vehicle

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