A small, but important part of your vehicle's engine is the idle air control valve. This small valve is positioned onto the throttle body and controls the amount of air flowing into the engine. If this valve is dirty, or not working as it should, then your vehicle will not idle properly. Testing the idle air control valve is easily done with a few basic tools.
Step 1 - Remove Idle Air Control Valve
The idle air control valve is located on the top rear of the engine. Remove the two screws holding it in place and disconnect from the wiring harness.
Step 2 - Visually Inspect Valve
One of the easiest ways to test your idle air control valve is to simply look at it. Check to see if the valve stems have dirt on them or if they are burnt. Check the valve opening on the throttle body to make sure that there is solid contact between the valve and the stem.
Step 3 - Use Voltmeter
Turn the valve over until you see the valve openings. Set your voltmeter to ohms and touch each of the leads to one of the valves electrical contacts. You should see a reading of 0.00, but can be as high as 0.05. If it is more than this, the valve is faulty and will need to be replaced.