This procedure covers the removal and replacement of the Idle Air Control Valve on the 2015-2020 Ford F-150 3.5L EcoBoost engine to restore proper idle control.

Warnings

Tools required

Parts

• Idle Air Control Valve × 1 — Use OEM Ford specification
• Throttle body gasket × 1 — Use OEM Ford specification

Preparation

1. Ensure engine is completely cool to the touch
2. Disconnect negative battery terminal and wait 5 minutes for system capacitors to discharge
3. Remove engine cover by pulling upward on front clips and lifting off
4. Label and photograph all electrical connections before disconnection for reference during reassembly

Procedure

1. 1

   Access the throttle body assembly
   Locate the throttle body on the driver side of the engine between the intake tubes. Remove the air intake duct by loosening the hose clamps at both ends using an 8mm socket. Disconnect the crankcase breather hose from the intake tube and set the intake duct aside.
2. 2

   Disconnect throttle body electrical connector
   Locate the large electrical connector on the throttle body housing. Press down on the locking tab while pulling the connector straight back from the throttle body. Wiggle gently if needed but do not force.
3. 3

   Disconnect coolant hoses from throttle body
   The throttle body has two small coolant hoses for heating. Use pliers to slide the spring clamps back on each hose, then twist and pull the hoses off the throttle body nipples. Have shop towels ready to catch minor coolant spillage (approximately 2-3 oz per line).
4. 4

   Remove throttle body mounting bolts
   Remove the four throttle body mounting bolts using a 10mm socket. Keep track of bolt locations as they secure the throttle body to the intake manifold. Support the throttle body with one hand while removing the final bolt.
   Torque spec

   Mounting Bolts55 Nm (40 lb-ft)
5. 5

   Remove throttle body assembly
   Carefully pull the throttle body away from the intake manifold. The gasket may stick, requiring gentle twisting motion. Once free, inspect the throttle body bore and intake manifold opening for carbon buildup, dirt, or debris.
6. 6

   Remove and inspect old gasket
   Remove the old throttle body gasket from the intake manifold surface. Clean both the throttle body mating surface and intake manifold surface thoroughly using throttle body cleaner and shop towels. Ensure no debris falls into the intake manifold opening.
7. 7

   Clean throttle body (if reusing)
   If cleaning the existing throttle body, spray throttle body cleaner into the bore and wipe clean with shop towels. Do not use excessive force on the throttle plate. For IAC function, ensure the throttle plate moves freely and returns to closed position smoothly.
8. 8

   Install new throttle body gasket
   Position the new throttle body gasket onto the intake manifold surface, aligning the bolt holes and coolant passages. The gasket should sit flat with no wrinkles or folds.
9. 9

   Install throttle body assembly
   Align the new or cleaned throttle body onto the gasket and intake manifold. Ensure coolant passage alignment is correct. Hand-thread all four mounting bolts before tightening any of them.
10. 10

    Torque throttle body mounting bolts
    Using a torque wrench, tighten the four throttle body mounting bolts in a criss-cross pattern to 31.0 Nm (23 lb-ft). Start with the top bolts, then bottom bolts, making two passes to ensure even gasket compression.
    Torque spec

    Mounting Bolts55 Nm (40 lb-ft)
11. 11

    Reconnect coolant hoses
    Push the coolant hoses firmly onto the throttle body nipples until they seat completely. Slide the spring clamps back into position over the hose ends to secure them. Ensure clamps are positioned past the barbed section of each nipple.
12. 12

    Reconnect electrical connector
    Align and push the throttle body electrical connector onto the throttle body until it clicks into place. Verify the locking tab is fully engaged by attempting to gently pull the connector away.
13. 13

    Reinstall air intake components
    Reinstall the air intake duct, aligning it with both the throttle body and air filter housing. Tighten the hose clamps at both ends securely using an 8mm socket. Reconnect the crankcase breather hose to the intake tube.

Reassembly

1. Reinstall the engine cover by aligning the rear tabs first, then pressing down on the front clips until they snap into place
2. Reconnect the negative battery terminal and tighten securely
3. Do not start the engine until coolant level has been verified and topped off if necessary

Verification

• Check coolant level in the reservoir and top off to the COLD FILL mark if needed due to hose disconnection
• Start the engine and verify no coolant leaks from throttle body hose connections
• Allow engine to reach operating temperature while monitoring for proper idle quality
• Verify idle speed stabilizes between 600-750 RPM when warm with all accessories off
• Test idle stability with accessories on (A/C, headlights, heated seats) to confirm IAC function
• Use a scan tool to verify no throttle body related codes are present (P0121, P0122, P0123, P2176)
• Perform a test drive to verify proper throttle response and idle return after deceleration

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