It's under the intake manifold between the back of the engine and the manifold. There's 2 bolts holding it on. If you put the car on ramps you can get to it with a small ratchet from underneath. If it wasn't working because of a short or open circuit you would get a code so it might be just dirty. You could spray some cleaner down the hole in the side of the throttle body if you don't want to take it off. That leads to the iac.