While looking through another forum I'm on, I came across a chat session they had with the Dodge Engineers of the 09 Ram. The question was asked about a button to disable the MDS. Below is their answer. It's just like the LX cars as I figured it might be. With the exception of the Tow/Haul mode of course

"Currently there are no plans to offer a disable button. Dodge engineers have worked very hard to make the MDS system completely seamless to the driver, offering 4 cylinder fuel saving mode when possible, and offering maximum power when it is demanded. You can disable MDS by placing the vehicle in Tow/Haul mode or by manually shifting to any lower range using electronic range select (ERS)."

 

true....

 

Thanks for the info. I had asked for someone that had the MDS light on their dash for help about this exact question, but got no feedback. Are you saying that any position with the auto stick other than "D" will kick out the MDS? The same applies for tow/haul mode?

 

Yes, that's what they are saying. Which kind of makes sense because this is how the LX cars are as well.

 

If this is correct, then the harmonic vibration in my hemi has nothing to do with kicking out 4 cylinders by the MDS.

 

Yep, it is still there even when MDS isn't active.