Originally Posted by Grimass
I'm pretty sure that 'Eco Mode' and MDS are not mutually exclusive. The v6 and 4.7 both have ECO Mode lights as well (Neither have MDS). My Guess is the light comes on when the system sees neutral or negative vacuum.
The Eco Mode light can mean different things for different model years, or different trim levels/motors.
On mine with the MDS Hemi, it means MDS is active.
From what I understand, the '13's with MDS and VVT, the light means VVT is active, and no message at all for MDS.
I would suspect the same of the V6 motors, that the light just means VVT is active since there is no MDS.
Just my .02, hopefully helpful.