I doubt that the suspension is affecting the ASR etc. The car's electronics communicate on a Car Area Network. (CAN) So if the programing sought to call for those parameters I suppose it could cause a issue, But I highly doubt that that's the case. Perhaps a fly by wire genius like Roncallo might have a thought. He pulled a complete M120 and all associated wiring and computers out of a Sl600 and stuffed them into a 107. That car of course has no hydraulic suspension. Therefore no sensors.
I grabbed the switch and interestingly enough they call it "switch accelerator control". I put an ohm meter on it and it is open when the pin in NOT depressed. When you press the pin it gives 993 ohms of resistance. So not a dead short as I thought ! Interesting. I felt the wiring on my car, it goes from near the top of the accelerator pedal then behind the panel on the drive line tunnel. As you can see the cable is fairly short. So perhaps you can chase that connection and test yours. Victor from New York had a video of him testing a SL500 TB. Unless he had a brick on the pedal when he moved the throttle arm manually, it kicked out. When he depressed the pedal enough to press that switch, everything worked as advertised. That is what I postulated MAY be your current issue. Of course that would be too easy! Amongst all the other things, it's worth checking. Have you used the on board diagnostics in the computer bay to look for error codes ? And erased them ? Another worthwhile thing. Keep up the good work ! You are still around $ 124,000.00 to the good aren't you ?
PS, since you are not familiar with the 600, The accelerator pedal is feather light, and has very minute movement when all is well, that and it is way too easy to hit 88 mph and go back to the future
If it feels like you are driving a 1956 GMC truck, the fly by wire servo throttles are NOT working. You are driving with manual cable throttle on the passengers side 6 cylinders. That's the Limp Home Mode. Generally makes a lot of things limp