MDS?

[mohemipar]

Hmm, i never see eco come on when im in tow/haul on the highway

Eco doesn’t mean MDS is on. You probably aren’t getting the Eco light in T/H because the shift pattern change is causing worse MPG by running higher RPMs. Eco only comes on when the truck calculates you are driving efficiently, not just because MDS is on.

Correct Tow Haul only disables MDS on HD models.

 

[mondo]

Eco doesn’t mean MDS is on. You probably aren’t getting the Eco light in T/H because the shift pattern change is causing worse MPG by running higher RPMs. Eco only comes on when the truck calculates you are driving efficiently, not just because MDS is on.

Correct Tow Haul only disables MDS on HD models.

Well hell, i was miss informed then...lol. Thanks for the info.

 

[McBroom]

Didnt realize they put a 5.7 in a 2500/3500...

2014 and older 2500/3500 did have the 5.7. I think it was switched to the 6.4 on the late 14 model and became standard in 15 up.


I Love My 2018 RAM 2500HD 4x4 6.4L. USMC (ret)

 

[mohemipar]

Surprisingly the 5.7 was still the standard HD engine until just recently. When I was a few months out from ordering my 2017 Laramie they were just transitioning the 6.4 as the standard engine option in Laramie and up trims. By the time I ordered in late winter 2017 it was standard at no cost. Big Horns and lower still had the 5.7 standard and the 6.4 as only a $500 (I think) option. Not sure if they did standardize the 6.4 across all trims before 2017 MY ended, but certainly for 2018 they don’t put the 5.7 in any HDs anymore.

 

[GIJoe2010]

I disabled MDS with my DS T1000. The “ECO” light still comes on in the dash when decelerating or cruising with cruise control.

Best decision I ever did with my tuner, as I got sick of constantly putting the trans in “8” to keep from the engine jumping in and out of MDS.

Mileage has gone up maybe .5 to 1MPG in town and no change on the highway. The best part is the no lag from MDS to non-MDS when accelerating.

 

[Granite Ram]

I have been turning off my MDS now for about three weeks and I went from low 15’s/100km to low 14’s/100km.

Drives like they used to before MDS and they had a throttle cable.

 

[Offthehook]

Tow/Haul mode does disable MDS in the 1500s. I've never seen ECO mode kick in when using T/H either. Some people have the impression these two are linked and that is false. I do believe they are linked in the 2500/3500 trucks but not 1500s. Just because ECO pops up on the display does not mean MDS has activated. It only means your driving style at that particular moment is the most economical.

 

[RLJ10X]

Eco Mode, MDS, Lie-o-meter, calling a glorified 4 speed a 6 speed....... it's all ********.

 

[Fitz-0518]

MDS. "MORE DIGITAL DUMB ****" But,,we should be fair to Ram engineers. They met the marketing and GPM demands they were given AND thought about the owner. Easy to disable. (As an old guy there are three digital things that I enjoy) The delete button on my PC. The ignore function on our forum and the MDS disable button.
I am sure that there is some gas savings with this feature. But I bought a 8 cylinder engine not a four banger. It runs best and meets my expectations when all 8 cylinders are getting air, fuel and spark.

 

[gregs2018ram]

same here. I disable MDS every time I put the vehicle in drive!... Its so annoying.

A waste of what?
My fuel mileage is the same with it off as with it on.

 

[gregs2018ram]

Actually, its - to get the display up, then + to get up to 8.

You can do it if you're driving, but you better only hit - once, otherwise it will downshift into the next lower gear. hit + to progress to a higher gear up to 8, and the truck will shift thru all the gears automatically and no MDS.

I accidentially hit - twice and it downshifted from from second to first abruptly.

Yes that's completely normal. It kind of lugs in MDS and it takes a split second for it to switch back to 8 cylinders. You can use the +/- buttons on the steering wheel to temporarily disable it and to see if that is what you're experiencing. After you put it in gear just push the minus button on the right side of the steering wheel until an 8 appears in the cluster where the gear numbers are.

 

[Dusty]

No.

MDS is NOT disabled in the Tow/Haul Mode on trucks with the 8HP70 8-speed. On 1500s with the 545RFE/645RFE 6-speeds, MDS was disabled in Tow/Haul Mode.

Best regards,
Dusty

2014 Ram Big Horn 1500 Quad Cab 2WD, 5.7 Hemi, 8HP70, 3.92 LSD, factory dual exhaust, 20” wheels. Now at: 076574 miles.

 

[tomb]

I try to remember to shift up to 6th gear in my case of 6speed-before take-off-but often forget--will I do damage to the tranny if I do so while I am driving? I have been to scared to try it! Anyone know if its safe? Thanks.

 

[Hemi395]

MDS is NOT disabled in the Tow/Haul Mode on trucks with the 8HP70 8-speed. On 1500s with the 545RFE/645RFE 6-speeds, MDS was disabled in Tow/Haul Mode.

Best regards,
Dusty

2014 Ram Big Horn 1500 Quad Cab 2WD, 5.7 Hemi, 8HP70, 3.92 LSD, factory dual exhaust, 20” wheels. Now at: 076574 miles.

MDS is not disabled in T/H on my 13 6 speed. I was towing my TT last fall and heard MDS kick in briefly on a slight down grade. I remember looking at the dash to make sure it was in T/H and sure enough it was.

 

[RysRam]

MDS is not disabled in T/H on my 13 6 speed. I was towing my TT last fall and heard MDS kick in briefly on a slight down grade. I remember looking at the dash to make sure it was in T/H and sure enough it was.

Seconded. I have a '13 6 speed and It's only come on a few times when towing (with tow/haul on) but it definitely does.

 

[Dusty]

Seconded. I have a '13 6 speed and It's only come on a few times when towing (with tow/haul on) but it definitely does.

Correct. I stand corrected.

After 2012, if the transmission is list as a 645FRE and the vehicle manufacturing date is after Oct 2012, the MDS will not be defeatured in Tow/Haul Mode.

My apologies.

Best regards,
Dusty

2014 Ram Big Horn 1500 Quad Cab 2WD, 5.7 Hemi, 8HP70, 3.92 LSD, factory dual exhaust, 20” wheels. Now at: 076633 miles.

 

[Fitz-0518]

Correct. I stand corrected.

After 2012, if the transmission is list as a 645FRE and the vehicle manufacturing date is after Oct 2012, the MDS will not be defeatured in Tow/Haul Mode.

My apologies.

Best regards,
Dusty

2014 Ram Big Horn 1500 Quad Cab 2WD, 5.7 Hemi, 8HP70, 3.92 LSD, factory dual exhaust, 20” wheels. Now at: 076633 miles.

MDS and oil are the high volume threads. What about 2018 66RFE. Is MDS disabled in tow haul mode??

 

[Fitz-0518]

Hello Bama1781,

You got some great advice here. If you decide you'd like to get this looked at by the dealer, let us know. Send us a direct message as we'd be glad to help with that process.

Jasmine
Ram Social Care Specialist

Great jump in offer. But, how about you folks engaging this huge issue with factory facts. The owners manual is horrible on this feature/function.

 

[gregs2018ram]

I try to remember to shift up to 6th gear in my case of 6speed-before take-off-but often forget--will I do damage to the tranny if I do so while I am driving? I have been to scared to try it! Anyone know if its safe? Thanks.

 

[gregs2018ram]

If you waited til you were in 6th, and hit - once, you would deactivate MDS.

If you waited til you were in 6th and hit - twice, you'd end up in 5th. With the 6 speed tranny.

If you have the 8 speed, same applies, but you'd be in 7th if you hit - twice, if you'd previously hit it to turn off MDS.

What I did one day was hit it twice when I first took off, so, essentially, it put me in 2nd, then when I hit - again, it revved me back up to first, and i was accelerating.

If you're going to do this to turn off the MDS, just wait til you're in 8th (in the 8 speed)