What are the common causes of P0518?

An intermittent break in the idle air control wiring. A loose idle air control connector. A dirty idle air control valve that sticks at times. A failing idle air control valve motor.

Wiggle test the idle air control wiring at idle. Command the idle air control valve and watch for a dropout. Clean the idle air control valve. Replace the idle air control valve if it sticks intermittently. Clear the code and retest.

P0518

Idle Air Control Circuit Intermittent

System: Speed and idle control (P code)
Lamp: Check Engine Light
Category: Powertrain - Computer and Auxiliary Controls

What it means

P0518 means Idle Air Control Circuit Intermittent.

Check these first

An intermittent break in the idle air control wiring
A loose idle air control connector
A dirty idle air control valve that sticks at times
A failing idle air control valve motor

What to do next

Wiggle test the idle air control wiring at idle
Command the idle air control valve and watch for a dropout
Clean the idle air control valve
Replace the idle air control valve if it sticks intermittently
Clear the code and retest

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Updated

Generic SAE J2012 definition. Last updated 2026-10-10.