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Question for you smart people about MDS

ollicat

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Hello all, I have a 2023 Hemi Laramie Mega Cab with MDS. As I drive, I see the Eco light come on which indicates I am now driving in 4 cylinders due to low horsepower demands. My question for you engine nerds is, why doesn't the truck go into 4 cylinder MDS mode when idling? It would seem to be a perfect time to go to only 4 cylinders to save gas. I know we all hade MDS but since we are stuck with it . . .
 
At idle to he truck is at a low load - no MDS. That's why some trucks and cars have ethe AUTO STOP - where the engine shots down at a full stop then starts back up when you let off the brake.

The HD trucks have neither - thank god.
 
I second this! Partially the reason I stayed away from the 1500 Ram.
We just got a 2021 Jeep Wrangler with the 2.0L turbo. It has the stupid stop/start feature. It defaults to ON every time you start the engine so you have to push the button every time to shut it off, just like the exhaust brake on our 3500. As far as I understand, these buttons toggle a setting in the computers through the CAN bus so it’s not a matter of installing a relay that can toggle the switch for you when you start the engine. If I am wrong here, please correct me.
 
We just got a 2021 Jeep Wrangler with the 2.0L turbo. It has the stupid stop/start feature. It defaults to ON every time you start the engine so you have to push the button every time to shut it off, just like the exhaust brake on our 3500. As far as I understand, these buttons toggle a setting in the computers through the CAN bus so it’s not a matter of installing a relay that can toggle the switch for you when you start the engine. If I am wrong here, please correct me.


 
At idle to he truck is at a low load - no MDS. That's why some trucks and cars have ethe AUTO STOP - where the engine shots down at a full stop then starts back up when you let off the brake.

The HD trucks have neither - thank god.
OK I kind of understand. But when highway cruising, I am under low load, hence the ECO light comes on and 4 cylinders shut down. I would think idling would be the same. In fact, if I have to shut down cylinders, I would rather do it idling than cruising.
 
We just got a 2021 Jeep Wrangler with the 2.0L turbo. It has the stupid stop/start feature. It defaults to ON every time you start the engine so you have to push the button every time to shut it off, just like the exhaust brake on our 3500. As far as I understand, these buttons toggle a setting in the computers through the CAN bus so it’s not a matter of installing a relay that can toggle the switch for you when you start the engine. If I am wrong here, please correct me.

My wifes 17 Jeep has that, and it stopped working, found out if the secondary battery for the stop/start doesn't have enough juice it disables it. Although i also found out if i slowly release brake pressure as I come to a stop it will not shut off, so it seems to also monitor brake pressure.
 
This may be known already to OP, but you can disable the MDS by pressing the gear limit "-" minus sign once, and then press the "+" until it shows the max gear in your dash as "8." you have to do each time you start the truck, but will disable MDS if you desire
 
When stopped, the engine needs to turn round to maintain the accessories and avoid vibrations, which is probably why the MDS does not activate. Personally, I prefer that it stays in V8 at idle rather than having an engine that grazes.
 
This may be known already to OP, but you can disable the MDS by pressing the gear limit "-" minus sign once, and then press the "+" until it shows the max gear in your dash as "8." you have to do each time you start the truck, but will disable MDS if you desire
does this work only on the diesel trucks? I don't have a gear indicator on my Hemi
 
Am I the only one who liked the eTorque 48v implementation in my 1500? Never had a single issue with it in 5 years i had my 2019. Far and away the best implementation of any start/stop tech I've had the (dis)pleasure of using, and a huge part of that was not using a conventional starter. Would have been fine if my 2500 came w/ eTQ (though I wouldn't have wanted to add another $2500 to the price or whatever).
 
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