Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Idle Control System
See IDLE AIR CONTROL (IAC) SOLENOID under SOLENOIDS under RELAYS & SOLENOIDS. Curb idle and fast idle speed are controlled by Powertrain Control Module (PCM) and are not adjustable. Some throttle bodies have a sludge-tolerant design with a special coated throttle bore. A Yellow/Black warning decal on these units warns against backing off throttle plate adjustment screw to avoid throttle plate sticking in bore. Faults in idle control system components or circuit should set a service code. See QUICK TEST in appropriate TESTS W/CODES article in the ENGINE PERFORMANCE Section.
NO RELATED
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.