Idle Air Control Valve

This procedure covers the removal and replacement of the Idle Air Control (IAC) Valve on the 6.7L Cummins diesel engine, which controls idle speed and airflow during engine warm-up and idle conditions.

Warnings

Tools required

Parts

• Idle Air Control Valve × 1 — Use OEM Mopar specification
• IAC valve gasket/O-ring × 1 — Typically included with IAC valve

Preparation

1. Park vehicle on level surface and apply parking brake
2. Allow engine to cool completely (minimum 2 hours after operation)
3. Disconnect negative battery cable and wait 2 minutes for system discharge
4. Remove engine cover by pulling upward on cover retaining grommets
5. Clean area around intake manifold and throttle body to prevent debris entry

Procedure

1. 1

   Locate the IAC valve or throttle valve actuator
   On the 6.7L Cummins, locate the intake air throttle valve on the driver side of the intake manifold near the turbocharger outlet. The actuator is mounted to the intake tube between the intercooler and intake manifold. Verify the component by tracing the electrical connector.
2. 2

   Disconnect electrical connector
   Press the locking tab on the electrical connector and carefully pull away from the IAC valve actuator. Inspect connector pins for corrosion or damage. Do not pull on wires directly.
3. 3

   Remove intake air ducting if necessary
   If access is restricted, loosen the clamps on the intake air duct between the air filter housing and turbocharger inlet. Remove the duct to provide clear access to the throttle valve actuator mounting hardware.
4. 4

   Remove IAC valve mounting fasteners
   Remove the mounting screws or bolts securing the IAC valve actuator to the intake manifold or throttle body housing. Support the valve during removal to prevent it from falling. Note the orientation and position of any alignment pins or tabs.
   ℹ️Some models may use mounting bolts instead of screws. Verify fastener type before applying torque specifications.
   Torque spec

   IAC Valve Screws3 Nm (2 lb-ft)
5. 5

   Remove IAC valve assembly
   Carefully pull the IAC valve straight out from the mounting bore. Slight twisting motion may be needed to break the gasket seal. Avoid prying against aluminum intake manifold surfaces which can cause damage.
6. 6

   Inspect and clean mounting surface
   Remove old gasket material from the mounting surface using a plastic scraper or soft wire brush. Clean the bore thoroughly with electrical contact cleaner and shop towels. Inspect for cracks, warping, or damage. Ensure no debris falls into the intake manifold opening.
   ⚠Cover the intake manifold opening with a clean shop towel to prevent debris entry while cleaning.
7. 7

   Prepare new IAC valve
   Remove the new IAC valve from packaging and verify it matches the original unit. Install the new gasket or O-ring onto the valve body, ensuring it seats properly in the groove. Lightly lubricate the O-ring with clean engine oil if specified by manufacturer.
8. 8

   Install new IAC valve
   Align the IAC valve with the mounting bore, ensuring any alignment pins or tabs are properly positioned. Insert the valve straight into the bore until it seats flush against the mounting surface. Do not force or cock the valve during installation.
9. 9

   Install and torque mounting fasteners
   Install the mounting screws and tighten by hand until snug. Using a torque wrench, tighten the IAC valve screws to specification in a cross-pattern sequence if multiple fasteners are present. Verify the valve is seated evenly.
   Torque spec

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

    Reconnect electrical connector
    Push the electrical connector firmly onto the IAC valve until the locking tab clicks into place. Verify the connection is secure by gently tugging on the connector body (not the wires).
11. 11

    Reinstall intake ducting
    If removed, reinstall the intake air duct between the air filter housing and turbocharger. Tighten duct clamps securely but do not over-tighten to avoid damaging rubber couplings.
12. 12

    Reinstall engine cover and reconnect battery
    Press the engine cover back onto the retaining grommets until it clicks into place. Reconnect the negative battery cable and tighten the terminal clamp securely.

Reassembly

1. Ensure all electrical connections are secure and properly locked
2. Verify no tools or shop towels were left in the engine compartment
3. Double-check that all intake ducting is properly sealed and clamped

Verification

• Start the engine and verify smooth idle with no hunting or surging
• Check for air leaks around the IAC valve mounting area (listen for hissing)
• Verify no diagnostic trouble codes are present using a scan tool
• Allow engine to reach operating temperature and confirm idle speed returns to normal specifications (approximately 700-750 RPM)
• Test drive vehicle and verify proper throttle response and idle quality during warm-up and when returning to idle after acceleration

Related trouble codes on this vehicle

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