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0rion
June 15th, 2016, 10:30 AM
Truck is an 06 duramax


I'm running v7.5 and can't get the speedo to do a fine tuning calibration. It shows the percent correction I need to do to H0101 but the pulses numbers don't show up and I can't manually change H0101. What am I missing here? I can change tire settings so I could guess at those until I get it correct but if there's an easier way I'd rather do it that way.
0rion
June 15th, 2016, 10:48 AM
Ok....I see when I highlight the final drive table it says the calc's don't work on the LBZ and LLY trucks. So I guess I have to figure out those revs/km and put them in manually?
0rion
June 15th, 2016, 12:01 PM
little confused....my revs are correct for the 285/75/16 tire I have on there. It's just not correcting the speedo. What's the trick here to get it to read correctly?
GMC-2002-Dmax
June 15th, 2016, 02:12 PM
Measure the rear tire, enter the rollout manually and that gets it spot on. Tires vary in height due to weight of vehicle, air pressures, etc. Entering the actual height always works for me.
0rion
June 15th, 2016, 02:30 PM
I could see a few tenths being the difference between tires but 4 mph? That's inches off. I will however measure it and see what I get. It's like it overshot it....when I'm at 60 my actual speed is 56. It would really help if the fine tune calc's worked...it'd be as simple as entering in speeds and applying it.
Road
June 15th, 2016, 02:50 PM
I could see a few tenths being the difference between tires but 4 mph? That's inches off. I will however measure it and see what I get. It's like it overshot it....when I'm at 60 my actual speed is 56. It would really help if the fine tune calc's worked...it'd be as simple as entering in speeds and applying it.
Just make your own correction factor by mutiplying by the error
0rion
June 15th, 2016, 05:48 PM
speedo is off 6.5% so I would apply that same factor to tire size? What about shift points? Same factor?
Road
June 16th, 2016, 08:48 AM
speedo is off 6.5% so I would apply that same factor to tire size? What about shift points? Same factor?
Yes but I don't use the shift point correction much. The speedo correction is hit and miss too many variables plus converting from hex to decimal then back to hex leaves room for error. Sometimes just to make corrections.