It is not the throttle position switch. It may be the air by pass or some call it the idle control, it may be stuck open. Most times when they get dirty the idle goes very low not high though. There is a small adjustment screw on the throttle body but unless you have made any adjustments before this problem came up it is not the problem either. I'd look for a vacuum leak as the cause.
There is no idle adjustment. The idle is adjusted electronically by the PCM controlling the idle air control valve. There may be a vacuum leak or problem with the IACV.
It is probably a Throttle Position Sensor or Idle Control valve malfunction - EFI doesn't really lend itself to idle adjustment to fix a high idle condition.
Like the other person said your throttle position sensor, you can buy a cleaner at auto zone take it off and clean it, our camry used to do the same thing, when I unplugged it, it stopped so I figured it was it, ot mayne yout throttle body is just very clogged and needs some cleaning as well
When I start my 2001 grand Cherokee its idling high and continues even after you start driving
