No idle air control motor on this
It has a very early electronic throttle system, kind of a mix of mechanical and electronic
There’s a motor on the electronic throttle body, and no cable attached there
But there IS a cable going from the accelerator pedal to the accelerator pedal position sensor, which is in the engine bay.
Since you’ve already cleaned the throttle body, I’d say next free thing is to make sure there’s no obvious and/or physical problem with the pedal, cable and that sensor I mentioned
After that, take it in to a shop. I suspect once somebody hooks up a scanner and gets a hold of the wiring diagram for the throttle controls, they’ll figure it out within a reasonable amount of time
If you aren’t able to somehow fix it on your own, have it towed to a shop. Far too dangerous to drive, if you can’t trust the throttle
You said there’s no check engine light, but there might still be some meaningful codes, but ones which are not commanding the check engine light to turn on
My gut feeling . . . without being there and having access to the car . . . is that something is wrong with the cable or that sensor
But don’t go replacing expensive parts just because some guy on the internet had a gut feeling
Are you handy?
Do you have a digital multimeter?
I believe you could easily test that sensor. Since it has a 5V reference, it could be tested as if it were a tps, I would think.
It’s been awhile since I worked at that Benz dealer, but that’s a pretty old car and not that complicated, not compared to some of the newer cars out there