Does anyone know how to recalibrate the speedometer on the MM3 tuner? My speedometer is showing me 2mph slower than I am actually going. Thanks
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Does anyone know how to recalibrate the speedometer on the MM3 tuner? My speedometer is showing me 2mph slower than I am actually going. Thanks
WelcomeOriginally Posted by RyanMc
It's pot luck with the MM3. Mine reads 2 to 3 MPH fast with over sized tires and a lower gear set. No matter what I do, it stays the same. It's not the local tuning as much as it is with the firmware in the MM3. Honestly? As long as you have no other issues with the truck, I suggest you just get used to it.
If I want an accurate speed, I just rely on the GPS.
2003- 3500 RWD Automatic. S & B intake, BD Intercooler, Pusher Air Horn, MM3 Double R Tuning, Turbo Timer, electric Flex-a-lite fans, FASS 95, 50 HP tips, upgrade to 351 turbo, 3.42 gears, Twin air compressors, air bags, Remote dual oil filters, Hellwig sway bar, Front Winch. Home made Fuel Heater, BD Exhaust brake with Torque Lock. Tons of TLC
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2012 Cummins Ram 6.7L MM3 tuner full 5" Flo Pro TBE Exhaust LWBCC 4x4 Mag Hytec Double Deep Transmission Pan , Mag Hytec Rear Diff Cover
Airlift part # 57595 7500lbs airbags ,Nitto Ridge Grapplers 35/12.50/20 on XD 829 Big Hoss ll Satin Black Machined Dark Tint 20 x 9 with + 18 offset rims,MM3 Tuner With full Custom Tunes by Ray at DRD , Autometer A13117 Pillar Pod , Edge 98004 mount adapter , Mag Hytec front diff cover, SuperNova V4 LED Headlight Bulbs
My 15 Ram has always been 3 off. I would set the cruise at 73 to run 70. And now with one size bigger tires tires it has reversed on me. That’s with a stock truck no tunner.
Change the tire size by like .1 at a time till it gets right. My speedometer is right on now. I think it's under ECM then ABS, I can look this afternoon to comfirm.
to the forum @RyanMc
I don't have the MM3 but they are usually the same. It was correct that you increase or decrease the tire size on your unit to obtain the correct speed-o to actaul speed. Read your manual to adjust the tire size, measure the actual tire size, adjust the MM3 to this measurement, get a Garmin or TomTom from someone and get on the highway. Check how close you are to the actual speed, and pull over to adjust as needed. Then verify. It takes a bit of time, but your good to go from there on. Note: write down the orignal measurement on the MM3 incase your sell or want to go back to original tires.
The manufactures normally set the speed-o to read 2 mph less that actual speed from the factory. The government wanted this so you will so call never exceed the posted speed limit. I believe they should be accurate and no fudging like they do, but who can fight the government. Been this way since I believe the late 40's to 50's.
Jim
2006 ~ 2500HD, Big Horn Edition, 5.9, 4x4, Q/Cab, 48RE, L/B, 3.73, S&B CAI & Snout, ProFlo 5" S/S exhaust, Smarty Touch, Oil ByPass Kit, 60 gal main tank, 110 gallon in-bed tank, XX-Fuel Filter System, Coolant Bypass Kit, Mag-Hytec front & rear end covers and trans pan, 285 x 70 x 17
"Freedom is never more than one generation away from extinction. We didn't pass it to our children in the bloodstream. It must be fought for, protected, and handed on for them to do the same, or one day we will spend our sunset years telling our children and our children’s children what it was once like in the United States, where men 'were' free." ~ Ronald Regan
Rob See liked this post
Did you adjust in the Ecu- Abs menu as close to exact tire size per manufacturer? Goes by .5" only. If you did then you have to just play with the sizes until it matches both your GPS on your phone and truck. I got my tire specs...33.85" per Nitto. Plugged it in at 34" at first and got 1mph less on both speedo and mm3. Switched it to 33.5" and now it reads as close to accurate on the GPS and mm3. If not @Double R Diesel can help.
2012 Ram 3500 HO w/4.10
Hellbent 2.5 level Bilstein 5100's
Double R Diesel Warp tunes
HPP egr delete
FloPro 5" w/muffler
CCV filter delete hose reroute to frame
Thanks. I had reached out the other day and he walked me through it
It seems to be working better on the later 4th gens. Mine is a rare MM3 third gen. It was an experiment that never went any further. But it works better than the Smarty for me.
2003- 3500 RWD Automatic. S & B intake, BD Intercooler, Pusher Air Horn, MM3 Double R Tuning, Turbo Timer, electric Flex-a-lite fans, FASS 95, 50 HP tips, upgrade to 351 turbo, 3.42 gears, Twin air compressors, air bags, Remote dual oil filters, Hellwig sway bar, Front Winch. Home made Fuel Heater, BD Exhaust brake with Torque Lock. Tons of TLC
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