The only way I can tell my MDS is functioning is the light on the dash comes on. Push the tow button and it never comes on. I live in a rural mountain area and the only time I see the MDS light is going downhil.
This is thanks to big advances in computer programming/ algorithms in control of automobiles. I remember in the 90's when GM started using "Cubed Logic" (AKA "fuzzy logic") to control shift quality AND to make TCC (torque converter clutch) engagement and disengagement almost imperceptible.
I was an automatic transmission specialist back then, and saw many failures of torque converters prematurely.
For purposes of CSI (Customer Satisfaction Index) I would modify the valve bodies of the GM transmissions to apply the converters more aggressively in order to extend the life of the transmissions. Nowadays, advances in this logic control have made the need to do that pretty much a thing of the past.
In those days, shift adaptive learn was having growing pains wherein say, the wife's Suburban was driven by Hubby for the weekend, or a trailer had been pulled, the algorithm would "adapt" to those driving habits and modify shift timing and feel. Many times, after the wife got the SUV back for her Monday thru Friday soccer mom life, she'd bring the vehicle in with tranny shift "feel" complaints; most often late and harsh. We'd explain that the condition would self resolve after she'd driven a couple of days. That would satisfy all but the more priggish of drivers. In those cases, I'd reset "Adaptive learn" back to factory default and they would be more satisfied along with the admonition that it still would take a couple of day's driving to reset to her habits.
Advances in these cylinder deactivation systems have begun to exploit the "spring action" of the de-powered cylinders to act like buffering accumulators to absorb the shock of dropping half the engine's power changes. These changes are akin to the fact that some aircraft can't fly without computer control air surfaces.
Automotive ADAS is another example of leaping advances in safety technology. ADAS saved my wife and 2 of her girlfriends on a 2-lane highway in Oklahoma a number of years ago. It was the classic of some idiot turning left in front of them, into their paths, them going high speed. The woman who was driving told me that the car's computer (A Toyota Camry) took over accelerator, electric steering, and ABS/VSC and they wound up stopped on the opposite side of the highway, turned around, scared out of their minds, but unhurt!
