Speedo calibration on 3rd Gen Tacoma

On Rough Country’s website it say this about the speed calibrator:

“Rough Country’s Speedometer Calibration Devices don’t just simply change your in-dash readout, they update your vehicle’s ECM, ensuring accurate shift points and proper electronic stability control.”

So does the module actually affect the shift points? I thought it just corrected the displayed mph, odo, and mpg that is displayed. If it changes shift points, how does it interact with an ECU tune, since a tune definitely changes shift points?

 

Funny, I actually asked that exact question yesterday on the KDMax tune thread. They said it will not affect the tune but I’m not sure how that’s possible especially since one reviewer said it reset their ECU completely.

 

My guess would be the affect (effect?) is symptomatic. The truck shifts gears at specific points and speed is one of the factors in its decision-making. By correcting the speed, you restore the original logic. However, I have to wonder if the ECU is actually impacted by the inline correction. I thought all it did was intercept the speed on its way to the cluster and adjust based on the settings. Guess it's changing the value somewhere else in the data flow.

 

It doesn’t do anything for shifting. It only changes what’s displayed on the dash.

 

Nah. The claim is sales snake oil. It intercepts the signal, multiplies it by whatever ratio you set it at then sends that number to the display

This. As proven by using OBD fusion or the like while the speedo calibrator is installed. It will display the unmodified speed reading.

 

This is my belief as well.

In my experience, the shift points are most definitely affected.

 

In what way? Unless you have 34s or larger most of the shifting is done while there’s a speed difference of less than 3mph from stock.
Not trying to be obstinate or anything but despite the claim, there isn’t a remap or something programmed into the calibrator. I just don’t see how shifting at 32 instead of 30 would be noticeable if the changes are linear.
4/5 or 5/6 might be 5-7 mph different if you’re running tires that large

 

I’m also wondering how it affected shift points. Maybe your ecu reset and the tranny has relearned your driving style better than it had before?

 

I'm running 34s (285/75/17) and all I can say is, after they were installed, in addition to the obvious speedo being off, I noticed the shift points being off as well. A week later when my Hypertech arrived, installed it and speedo/odo/shift points immediately returned to normal.

 

Probably your imagination. Think about how it’s installed. It intercepts the signal going into the cluster and changes it. Your ECU has no idea that’s happening.

Shift points would have to intercept ECU or maybe via the OBD port.

 

Do you have a tune installed?

I had thought it only affected the signal to the instrument cluster, and though the CANBUS still puts out the original MPH.

If that is the case, there should be no change to shift points at all. It might look like it shifts at a different MPH, but that is because you are seeing the speed being sent to your gauges.

I could be wrong though so that is why I’m asking.

I never thought these speed modules would effect shift points or a ECU tune in any way, but I read the claim on RCs website, so I am super curious.

If it does change shift points, then my bigger question is how does that interact with KDMax, OTT, or any other current tunes.

 

I do not have a tuner / tunes installed. Regardless of what me eyes see on the instrument cluster, I can promise you that I felt a difference in shift points after the Hypertech install. Call it my imagination like @erok81 suggests, but I stand by my statement.

 

Those rat bastards! Is that not false advertising? I think it's disingenuous at best, snake oil at worst. If they're stating it, it's either a bald-faced lie or there's something 'technically' happening that makes them say it. Like me selling you a product that claims it will make me stop putting legos in your path to tread upon. Technically not wrong, but also wasn't an issue to begin with.

 

This may be a dumb question but does plugging this into a new truck void the factory warranty?

Harley does that if you plug in an aftermarket fuel map thingy. I know this doesn’t change the fuel map but i thought I’d ask anyways.

 

If they can prove with 100% certainly that whatever went wrong was caused by it specifically, probably. But not by simply having it plugged in

 

Installed the hypertech in my 23 sport today and it works great.

 

As far as shift points changing. The shift points are controlled by more than just wheel speed. Torque, throttle position and who knows what else is considered. Where are you getting enough comparable data to say that your shift points have been changed just by the speedo calibrator?

 

Shift points are not changed when using the in-line calibrator. Two different systems.

 

Have you noticed any issues with your turn signals not illuminating when you unlock the truck? And where did you get it from? I put one in my 21 a few days ago and the first time I unlock it in a while, I get no turn signals. And when I removed the hypertech, that stopped. It was pretty warm when I removed it. Got it from Amazon, it worked fine functionally but wondering if it’s a fake product or something wrong with it. Very odd.