MDS operation on Challenger 5.7 2018

[Benjamin Lopez]

Hi all, can anybody explain how the MDS-launching and its solenoids signals can be scanned? I tried to add signals to the scanner and I did only find "MDS active" "yes/no" but I don?t know what it means, and it confuses to me when the car is running it is always on "yes"..... I saw nothing else to monitor the MDS function and troubleshoot it. can anybody give guidance?

Background if anybody wants to have the full history:

My friends 5.7 has a problem and I am trying to help him investigate months ago, (LTFTs run always on -31 to -33 in all the table buckets, the car uses to shake hard back/forth when shifting during pedal release 8-7 or 7-6 gears, the FA enrichment reaches very high values and very often at partial load (higher than WOT limits), and it knocks a bit at partial throat. We have checked everything on the engine and its sensors, replaced O2 sensors, replaced IAT, replaced MAP, checked no leaks in intake manifold, checked injectors, fuel pressure.... TB and injectors part numbers verified, the active exhaust valves open and close normally, it has same symptoms in normal and sport mode... all looks good with the engine..... we are suspecting problem in the PCM now.

PCM: we observe the PCM has been manipulated as it is sealed with silicon. We went to Chrysler and paid to reload its original program, but no improvement after that. It took me very long to read its program with my HP Tuners (obviously bypass cable on): it failed to download 3 times for timing, until I finally could download it, I compared to a similar 5.7 2018-MDS and the program is exactly the same....

The last discovery is its MSD is not switching off the 4 cylinders at all. I would suppose you would notice that when driving, but for in case I plugged the HP Tuners scanner and we drove for quite long and soft, I monitored the 8 injectors pulses and they were permanently running in the same tenth of a millisecond, none did shut off other than when coasting down the 8 disconnected together and reconnected again later. We lifted the intake manifold this weekend to confirm the solenoids are installed.. and they are, while intake manifold out we checked no leaks by filling it with water (we already checked with smoke but to be sure)... no air leaks. The engine looks all stock in hardware although my friend is not the first owner, so we can?t be sure if any internals like cams were replaced, the engine does not look like having been opened at all.

We are planning to replace now the PCM with a used one reprogrammed by HP Tuners to stock, however before proceeding I am asking here if anybody can give me direction on how to scan properly what is going on with the MDS: is the PCM trying to launch it and it does not launch? is the PCM even not trying to launch it... are signals going to the MDS solenoids... ?? is there a way to monitor that all with the HP Tuners scanner?

Thanks in advance.