Speedo off 18 mph

[lmarceaux]

2008,Silverado,4wd 4:56,35 in tires,Yes been having a trinty for several years, only one problem till now, Last time the unit locked up had to send in, got back unit very quick and was unlocked,ya'll did not charge me.Now almost 2 years later the pcm starts to send out p0606 codes, been in the gm business long enough, pulled out tuner and went back to oem. Installed new unit and I programed the unit. then went to install tuner and the programmer would lock up. Contacted ya'll and was told I would need to update the unit. In the process the unit locked up. called ya''l and we tried to unlock but would not. So I was informed would have to send in.Cannot wait will do later, need truck for patrol in oil field on week end.
So went to Gary Watson racing and purchased a new one great guy to deal with. Done this a hundred times, now will take the DOD out but will not accept the axle ratio or tire size, will see it and will ask to install it will go thru process but drive it and still reads 18 mph off, did it till I was blue in the face, never had this type of concern, always took the ratio and tire size before, never took more than one try....... ,,please help...........

[mikel]

intune or trinity?
is the device up to date?

[lmarceaux]

Trinty, yes, Sent Garrett the backup and tune, thank you for your quick response, hope this can be solved.if you need the version's can get them for you.

[lmarceaux]

Old unit has version v.1r13k,6jy3w,new unit had v.1r13b,updated tonight did not get other version,6cbxy89,2008 Silverado,5.3,456 gears,35 in tires.

[mikel]

export the tunes from the tool using dsdownloader and post them here and we'll fix it in a custom tune.

[lmarceaux]

Mike I hope this download is correct ,thanks again. Axle ratio:4:56 Tire size 35/12.50/17

[Zach]

Please load the tune attached here, it's got the changes for the gears and tires

[lmarceaux]

Zach ,just uploaded the program, test drove truck, at 62 mph showing 70 mph,before was 18mph off,getting closer, and my abs lite comes, on. Ever since installed not this program but since all this started with the mph off the abs been coming on,with the orginal trinty and with the tune I loaded 3 years ago the mph been only 1 mph off, and the abs never came on. Did a tire height check, warm sitting parking lot, at 33.5 tall. I do not know if this will help, hope so, again thank you for working with me.