Toyota Repair: 1997 4Runner, air control valve, adjustment screw

Question
My 1997 4Runner runs well. The problem is that it idles at 500-600rpm. Especially when the A/C is running. Now I have adjusted the idle on the throttle body, but when I shut off the A/C, the idle will be too high. I do have engine light, and ABS light that are on. Would that have something to do with the idle?

Answer
Yes the engine light being on may have everything to do with the idle, by the way the throttle body adjustment screw is set and sealed at the factory and should not be adjusted, the idle is adjusted by the computer and the idle air control valve. I need to know what the diagnostic trouble codes are, can you get it to an autozone or similar parts store, they can help you get the codes at no charge.