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Im needing some help with speedo calibration there are 2 boxes for tire radius, 2 boxes for transfer case and 2 boxes for rear gear. Are the values supposed to be the same in each box? Or is this a before and current scenario? The description is less than helpful. i have tried changing the values and speedometr still reads 8-9 mph too slow. Please help
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The Tacoma only has one set of boxes, but I have adjusted them to match my new tires without any effect on the speedometer itself.. I have not yet scanned the OBD to see what the ECM is reporting (because I am lazy), but I suspect the ECM has its own internal speed reading that is separate from the speedometer cluster.
Can anyone shed some light on this?
Pretty much all Toyota's take the speedo cluster input direct from the ABS controller which calculates the speed from the wheel sensors. This signal is then passed on to the PCM which calculates it own vehicle speed for OBD2 and other things. Automatic vehicles will also calculate a backup vehicle speed value which is used in some transmission calculations. Most manufacturers make a complete mess of vehicle speed inputs and calculations, it seems Toyota is no exception... This means that changing these gear/tire values will not result in a change of the speedo cluster.
Good to know.. I don't suppose there's anything on the horizon allowing us to reprogram either the ABS controller or the instrument cluster itself to apply a correction factor? I know hypertech sells an inline speedometer calibrator but I'm having trouble justifying $220 on top of wheels and tires...
No plans at this time sorryQuote:
Originally Posted by njedwardz
chris any plans yet to allow speedo correction?
Waiting for this also. Hoping that HPTuner will be able to make this happen.Quote:
Originally Posted by rbosley2
I have a 2020 Tundra non flex fuel and have been trying to get my speedometer calibrated and cant seem to find the gear tire wizard either. I see the same options as the first post and when adjusting the measurements and doing a test drive the speedometer is still not corrected? I read on hptuners site that this was a feature now available unless I misread something. Any help is appreciated
Not capable of being done via HPT. You can update the internal speed calculations (and should), but the speedometer itself cannot be corrected via HPT.Quote:
Originally Posted by krod2020
The gear/tire wizard is only available on select platforms; not the biggest deal because the shift and TCC schedule are in terms of output shaft RPM on Tundras, so it's little less useful than it would be on a platform that references vehicle speed.
Stand alone board that you correct with a PC computer program. Looks reasonable price wise.
https://www.summitracing.com/search/...a/model/tundra
The Description under the Toyota tuning section is extremely misleading in the area of speedometer calibration https://www.hptuners.com/vehicles/toyota-tuning/ "Off-road features such as Gear/Tire Wizard, speedometer adjustment, and transmission support."
So does speedometer adjustment not mean adjusting the speedometer?
Now what do I do that I spent 4 license keys and an hour of my time making this work because I trusted what it said on the Toyota page? Seems like some bait and switch.