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 Air Control Valve
Disconnect Idle Air Control (IAC) valve connector. See IAC VALVE LOCATION table. Using an ohmmeter, measure resistance between IAC valve terminals. See IAC VALVE RESISTANCE SPECIFICATIONS table. If resistance is not within specification, replace IAC valve.
| Application | Location |
|---|---|
| Miata, 626 (2.5L) & Millenia (2.5L) | Under Throttle Body |
| Millenia (2.3L) | Part Of BAC Valve |
| MPV, Protege, Protege5 & 626 (2.0L) | On Top Of Throttle Body |
| Application | Ohms | ||||||
|---|---|---|---|---|---|---|---|
| Miata, Millenia 2.5L, MPV & 626 2.5L | (1) 8.7-10.5 | ||||||
| Millenia 2.3L | (2) 10.7-12.3 | ||||||
| Protege, Protege5 & 626 2.0L | (3) 7.7-9.3 | ||||||
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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.