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MDS

MobyDick

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I’m wondering is there a reflash or a update for this. My truck seems to cut cylinders way to often. I usually drive the truck around town with is disabled via selecting gear but the times I forget to do so it drives me and the wife crazy!


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Got my first one with MDS in 2015. After driving it a couple of months, I sorta stopped noticing it unless I was specifically looking for it. Now it's been 5 years and I never notice it on at all.
 
I had my '15 for @43K miles, and hated MDS every inch of the way. I tried to get in the habit of using the gear limit switch set to top gear, and prevent MDS from coming on. It is a worthless idea on a 7K lbs truck. One of their big spiels when the '19s were rolled out was the addition of "tuned mass modules" that would counter the harmonics, and allow MDS to come on even more than before.
 
I had my '15 for @43K miles, and hated MDS every inch of the way. I tried to get in the habit of using the gear limit switch set to top gear, and prevent MDS from coming on. It is a worthless idea on a 7K lbs truck. One of their big spiels when the '19s were rolled out was the addition of "tuned mass modules" that would counter the harmonics, and allow MDS to come on even more than before.

It’s ridiculous on how often it comes on. Every turn you make and lift off the skinny pedal it comes on. Then your having to roll into the throttle more when your through the turn


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Yep, it sounds more aggressive than the older version. Some simple testing on my '15 showed about 3 miles/gallon difference on flat ground at 55 mph when it's working. I definitely wouldn't want it in a sports car, but I got used to it and I don't drive the truck the same way as my cars. In my old '15 (a Rebel) it stopped kicking on at speeds above 65 unless I was going downhill. The increased resistance from air drag must cause enough load that it avoids activation. My '18 6.4 seems about the same as the '15 5.7.
 
I’m wondering is there a reflash or a update for this. My truck seems to cut cylinders way to often. I usually drive the truck around town with is disabled via selecting gear but the times I forget to do so it drives me and the wife crazy!


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I'm wondering if you didn't just identify a problem I have been having since day 1 in early September. I have yet to take the truck to the dealer, but that day is swiftly approaching with 5K miles. A good amount of time when I hit the accelerator at low RPMs (generally in the 1250-1500 range) regardless of speed, a horrible vibration occurs, along with a lack of power and the feeling that the engine is missing. The vibration is sort of the feeling you get when you run over the rumble strips on the side of an interstate. Friends who have been in the passenger seat have asked me what the heck was wrong. I have been hitting the tow/haul button and that fixes it, but I hate driving in tow/haul mode. In the last week or so, I decided I would just manually shift until the dealer could look at it. That of course worked. Then this morning I read your post. I had to drive somewhere today, so I put the high limit on eighth gear. Should be no different different than normal driving... right? No problems at all. The truck drove beautifully! No feeling of lugging and being in too high a gear. No vibrations. No feeling of engine misfiring. You think that is MDS? If so, I will never get used to it. I refuse to believe that isn't bad for the engine and maybe even the transmission. They either need to fix that or provide a way for the driver to permanently turn it off. It has been the most unpleasant part of owning this truck. I'm sort of hoping I am wrong and something is broken, because if it is normal operation for MDS, then I really have to wonder about this brand.
 
mine does the same over use of MDS .. from a stop lite on a 10 - 15% grade my trk will go from stop up the hill with the mds light on then continue on with only 4 cylds .... i have told my wife this trk only has 4 cylds .... don't get me wrong, i can see without the mds the mpg would be lower and when not in mds mode the trk has plenty of power .... her 2019 E torque does not run in mds near as much ....
 
mine does the same over use of MDS .. from a stop lite on a 10 - 15% grade my trk will go from stop up the hill with the mds light on then continue on with only 4 cylds .... i have told my wife this trk only has 4 cylds .... don't get me wrong, i can see without the mds the mpg would be lower and when not in mds mode the trk has plenty of power .... her 2019 E torque does not run in mds near as much ....
Is the "Eco" light the MDS light? FWIW- From what I hear it isn't. You can have the eco light be on and not be in MDS.
 
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Odd. I had a 2017 5.7L Rebel and now a 2019 6.4L 2500 and I have never noticed the MDS aside from the light on the dash that I have to work hard to get it lit up for a second. On both of mine, you absolutely, on no way, under any conditions.... could you start out and be in MDS mode. Any throttle beyond the lightest touch while on absolutely level or down slope will disable it. I actually have wished that it "worked" better, and by that I mean I wished that it would allow me to actually drive mildly and have it save fuel.

What I am saying is that the descriptions above are wildly different from what I have seen in my latest 2 trucks.
 
I'm wondering if you didn't just identify a problem I have been having since day 1 in early September. I have yet to take the truck to the dealer, but that day is swiftly approaching with 5K miles. A good amount of time when I hit the accelerator at low RPMs (generally in the 1250-1500 range) regardless of speed, a horrible vibration occurs, along with a lack of power and the feeling that the engine is missing. The vibration is sort of the feeling you get when you run over the rumble strips on the side of an interstate. Friends who have been in the passenger seat have asked me what the heck was wrong. I have been hitting the tow/haul button and that fixes it, but I hate driving in tow/haul mode. In the last week or so, I decided I would just manually shift until the dealer could look at it. That of course worked. Then this morning I read your post. I had to drive somewhere today, so I put the high limit on eighth gear. Should be no different different than normal driving... right? No problems at all. The truck drove beautifully! No feeling of lugging and being in too high a gear. No vibrations. No feeling of engine misfiring. You think that is MDS? If so, I will never get used to it. I refuse to believe that isn't bad for the engine and maybe even the transmission. They either need to fix that or provide a way for the driver to permanently turn it off. It has been the most unpleasant part of owning this truck. I'm sort of hoping I am wrong and something is broken, because if it is normal operation for MDS, then I really have to wonder about this brand.

That’s exactly what MDS feels like in my truck. Absolutely horrible! I now ONLY drive with 8th gear selected


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I'm wondering if you didn't just identify a problem I have been having since day 1 in early September. I have yet to take the truck to the dealer, but that day is swiftly approaching with 5K miles. A good amount of time when I hit the accelerator at low RPMs (generally in the 1250-1500 range) regardless of speed, a horrible vibration occurs, along with a lack of power and the feeling that the engine is missing. The vibration is sort of the feeling you get when you run over the rumble strips on the side of an interstate. Friends who have been in the passenger seat have asked me what the heck was wrong. I have been hitting the tow/haul button and that fixes it, but I hate driving in tow/haul mode. In the last week or so, I decided I would just manually shift until the dealer could look at it. That of course worked. Then this morning I read your post. I had to drive somewhere today, so I put the high limit on eighth gear. Should be no different different than normal driving... right? No problems at all. The truck drove beautifully! No feeling of lugging and being in too high a gear. No vibrations. No feeling of engine misfiring. You think that is MDS? If so, I will never get used to it. I refuse to believe that isn't bad for the engine and maybe even the transmission. They either need to fix that or provide a way for the driver to permanently turn it off. It has been the most unpleasant part of owning this truck. I'm sort of hoping I am wrong and something is broken, because if it is normal operation for MDS, then I really have to wonder about this brand.
Yes, that's exactly what MDS feels like when it kicks in. On my '17 I always put the gear selector in 6th gear when I drove it until I put a Pulsar in to disable it.
 
Odd. I had a 2017 5.7L Rebel and now a 2019 6.4L 2500 and I have never noticed the MDS aside from the light on the dash that I have to work hard to get it lit up for a second. On both of mine, you absolutely, on no way, under any conditions.... could you start out and be in MDS mode. Any throttle beyond the lightest touch while on absolutely level or down slope will disable it. I actually have wished that it "worked" better, and by that I mean I wished that it would allow me to actually drive mildly and have it save fuel.

What I am saying is that the descriptions above are wildly different from what I have seen in my latest 2 trucks.
My experiences are more like yours. I could only tell if I really paid attention when the MDS kicked on in the '15 Rebel. And it wouldn't kick on below about 25mph. But even a minor adjustment in pressure on the pedal would instantly kick it off. It's slightly more obvious on the '18 6.4L. But again, I have to be paying attention to pick up on it.
 
Is the "Eco" light the MDS light? FWIW- From what I hear it isn't. You can have the eco light be on and not be in MDS.
No. The ECO light is tied to a different circuit. When it kicks on, there is a good chance that the MDS is on, but it is not actually connected. At least not in the trucks I've had. BTW you can disable the light in the Uconnect menus, but that doesn't disable the MDS.
 
No. The ECO light is tied to a different circuit. When it kicks on, there is a good chance that the MDS is on, but it is not actually connected. At least not in the trucks I've had. BTW you can disable the light in the Uconnect menus, but that doesn't disable the MDS.
Thanks, that confirms what I read. I am wondering if I am missing a MDS light or people are talking about the ECO light, which really isn't MDS.
 
Odd. I had a 2017 5.7L Rebel and now a 2019 6.4L 2500 and I have never noticed the MDS aside from the light on the dash that I have to work hard to get it lit up for a second. On both of mine, you absolutely, on no way, under any conditions.... could you start out and be in MDS mode. Any throttle beyond the lightest touch while on absolutely level or down slope will disable it. I actually have wished that it "worked" better, and by that I mean I wished that it would allow me to actually drive mildly and have it save fuel.

What I am saying is that the descriptions above are wildly different from what I have seen in my latest 2 trucks.

This so weird. Three people are experiencing the issue and two aren't. I don't know how you are determining that MDS is on or off. The ECO light is not telling you that in a way that you can be sure of. I have never experienced anything moving from a start. It is always the same. I am moving along at any speed at sub 1500 rpm. The engine loses power when accelerating gently. If I had a manual transmission I would downshift at that point. It feels as if I am in too high a gear. Often a horrible vibration occurs about equal to running over a rumble strip on the side of the highway. This never happens in tow/haul or high gear limit mode. I've never experienced it on the interstate, but you don't go below 1500 rpm on the interstate. I guess I will let the dealer know because there are obviously people out there without the problem. There is no way, anyone wouldn't notice it. The vibration would wake up a corpse. Thanks for the info.
 
I played with mine yesterday and was able to create much of what folks here are saying that they feel. I have to drive unusually, maybe because I live in Western PA and it's hilly with little chances to be light enough throttle. But if I concentrate on it, I can get the results that they are talking about.

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Brucie, I’ve got a little over 8900 miles on mine and I haven’t experienced what you are describing either. The only way I have been really able to tell I’m driving with only 4 cylinders is when I really get into the gas pedal, then the acceleration between MDS and all 8 cylinders is a night and day difference.
 
I played with mine yesterday and was able to create much of what folks here are saying that they feel. I have to drive unusually, maybe because I live in Western PA and it's hilly with little chances to be light enough throttle. But if I concentrate on it, I can get the results that they are talking about.

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Were you able to experience the vibration? I am assuming that is some sort of harmonic feedback, which they were supposed to have addressed tn 19. My area is very flat. There is only 150 feet of elevation between here and the Chesapeake Bay around 50 miles East of here. The place I experience it the most is in my own neighborhood, driving in or out of it. I'm typically moving at 25 mph or less and accelerating very lightly when needed. I have experienced it at 40-45 mph too though. I doubt MDS gives you an extra .5 mpg in in-town driving. I'd leave it on for interstate driving, but see no value in-town. I'm wondering if the difference between the people that experience it and the people that don't has to do with the way the transmission is programmed. It just seems to be upshifting too early.
 
I couldn't create the vibration aside from one time. We have the new Baden Pa Walmart that was built in a hill top with a road curving up the slope to the store. I got it to go into MDS more and lug it up that slope and I could definitely hear it, and slightly feel a vibration in the floor, seat, steering wheel.... All of it. I tried to increase throttle a bit to see if I could make it get more dramatic but the transmission downshifted and killed that system.

On more level surfaces I can kind of hear that engine/exhaust sounds pitch change, but I couldn't find a way to make create a feel. Once I would try to accelerate normally it would leave MDS and you absolutely hear the engine pitch change and the sound smooths out.

Where I'm living and driving it's not much of a thing, we typically brake down long hills or throttle up long hills. But we destroy brakes, ball joints and tie rods get replaced multiple times in the life of a vehicle and we never ever see fuel economy that that most of the country claim to see. And we chemically destroy our vehicles in about 7 to 10 years with the snow and ice fighting chemicals. Around here, if you see a 15 year old truck or car, it's totally rusted and ugly. I drive to other parts of the country and see 30 and 40 year old trucks and cars that still look great. Must be nice!

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I couldn't create the vibration aside from one time. We have the new Baden Pa Walmart that was built in a hill top with a road curving up the slope to the store. I got it to go into MDS more and lug it up that slope and I could definitely hear it, and slightly feel a vibration in the floor, seat, steering wheel.... All of it. I tried to increase throttle a bit to see if I could make it get more dramatic but the transmission downshifted and killed that system.

On more level surfaces I can kind of hear that engine/exhaust sounds pitch change, but I couldn't find a way to make create a feel. Once I would try to accelerate normally it would leave MDS and you absolutely hear the engine pitch change and the sound smooths out.

Where I'm living and driving it's not much of a thing, we typically brake down long hills or throttle up long hills. But we destroy brakes, ball joints and tie rods get replaced multiple times in the life of a vehicle and we never ever see fuel economy that that most of the country claim to see. And we chemically destroy our vehicles in about 7 to 10 years with the snow and ice fighting chemicals. Around here, if you see a 15 year old truck or car, it's totally rusted and ugly. I drive to other parts of the country and see 30 and 40 year old trucks and cars that still look great. Must be nice!

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Having the vehicle vibrate is not something I can reproduce at will. It happens frequently, but it isn't predictable other than happening when the truck seems to be struggling with power.
 
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