MDS or ECO need some help...

I have a 2019 Hemi, and noticed on my maiden voyage from north to Florida, a green light on the dash that spelled out ECO, I believe. This has got to do something with gas mileage, I assume, but how do I get this to go back on to get best fuel mileage? I have a 900 mile trip Monday and it might help. Also, does the MDS kick in automatically? Thanks!

found my answer!

Most will tell you that the ECO light is only when MDS activates and there are some you will come across that will tell that other things are afoot too. The owner's manual is no help as all it will tell you is that the ECO light comes on when conditions are met for it to illuminate.

I'm not sure what else is involved but mine only seems to come on when my MDS is active. If you are light on the go pedal and are between 20 mph and 50 mph you should have no problem getting it to activate. I can cheat and speed up to a little above the speed I want to cruise at then back off a little to get MDS to kick in a little earlier. After that go easy (and steady) on the throttle and your ECO light should stay on as you cruise down the road.

Over 50-ish mph is a little harder since the engine has to do more work to maintain speed. I've had mine kick in as high as 65 mph but if it's not a slight downhill it won't stay active for long. If you are mostly coasting or going downhill I've had my ECO light come on at 70 mph.

brian, i thought the same. despite what pple said, mds and eco always seemed to work hand in hand. then when i went on trip last week, had mds disabled, eco popped on. once. and didn't stay on. i thought..hey!!!! could not duplicate the condition.

I have connected my OBD scanner to RAM 1500 2019 and I can confirm that ECO light is on when only four cylinders are active. Not sure about other years models...

The Eco ligjt will still come on when you disable MDS. Mine pops on when I hit 20mpg and above driving conditions on the moving meter. I have had MDS disabled for so long now, I don't recall if it actually came on only when MDS truly activated.

MarshRam said:

The Eco ligjt will still come on when you disable MDS. Mine pops on when I hit 20mpg and above driving conditions on the moving meter. I have had MDS disabled for so long now, I don't recall if it actually came on only when MDS truly activated.

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2014 model might be different from 2019...

Yep, my 2019 never comes on after I disable MDS.

Fatbob Frank said:

Yep, my 2019 never comes on after I disable MDS.

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My 2019 never comes on after I disable MDS too.

Turned off MDS for yesterday's commute (60 mile round trip with mixed driving). I usually have the ECO light on a lot with the light traffic coming into work and a fair amount on the way home. With the MDS turned off the ECO light did not come on once yesterday.