How Do You Check An Idle Air Control Valve?
• See if the “check engine” light is on. If it is, use an OBD II scanner to retrieve the codes if the car is 1996 or newer. • If the codes are between P505 to P509, you have a problem with the idle control system that might be the idle air control (IAC) valve. • Older cars may have a code that can be retrieved by an original OBD scanner. The code 11 signals the same idle control problem as newer cars. The diagnostic procedure is the same for both. • Disconnect your IAC valve and turn on your car. At this point your idle speed should rise like it’s supposed to. • Turn off your car and reconnect your IAC. Restart the car and your idle speed should go back to normal. If it does, your problem lies elsewhere in the system. Use a test light if the idle speed did not do what it was supposed to. Hook it up to the idle air control solenoid and watch the light. • The light will either flash or become dimmer for the four circuits if the valve is at fault. If it doesn’t, it means the wiring or the
