Hypertech Speedometer Calibrator (1 Viewer)

[BigSwede]

Now the question is, does it only fix the speed in the instrument cluster or does it actually correct it for the ECM/BCM/TCM.
On the website they cleverly stated the obvious that non-stock tires will through off the Transmission shifting but they technically only state it corrects the speedometer. "Part-throttle shifting" can mean that is changes the throttle response and not necessarily correct the speed signal in the computer.

To me if that's the case its not worth it, now if it also fixes the transmission shifting then I would be interested

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I suspect not. It consists of a little module and a wiring harness that inserts the module into wiring behind the instrument cluster. I doubt the ECM collects any data through that particular wiring.

 

[BigSwede]

I finally got around to installing the Hypertech Speedometer Calibrator today. Install is pretty easy, a video from GX BOB was useful in removing the instrument cluster. Only 2 screws and everything else pops off. The unit just plugs in inline with the supplied wiring harness.

Alas, the properly configured unit did NOT do anything to change the speedometer reading for my 2018 GX, so it is going back.

I wouldn't be surprised if this unit did actually work on older GXs... but I have no way of knowing either way.

 

[r2m]

I finally got around to installing the Hypertech Speedometer Calibrator today. Install is pretty easy, a video from GX BOB was useful in removing the instrument cluster. Only 2 screws and everything else pops off. The unit just plugs in inline with the supplied wiring harness.

Alas, the properly configured unit did NOT do anything to change the speedometer reading for my 2018 GX, so it is going back.

I wouldn't be surprised if this unit did actually work on older GXs... but I have no way of knowing either way.

So all that work was for not?
Just curious, why do you think it'll work on older GX's? Do you mean GX470 or the '10 - '13's?
My guess unless you had a 2022 or newer and it didn't work on that, then maybe, and that's a big maybe, it'll work on older GX's.
But I don't think there's really any difference behind the dash between your 2018 and my '13.

 

[r2m]

Just looked up Hypertech Speedometer Calibrator and they specify ALL our GX's!
And you say it didn't work?? Hummm. Something sounds hinky.

 

[BigSwede]

I talked to Hypertech tech support and they were able to view my unit's configuration on line and said it was correct, but when installed it had no effect on my speedo reading (I tried twice). No way to know if the unit was somehow defective otherwise.

 

[BigSwede]

So all that work was for not?
Just curious, why do you think it'll work on older GX's? Do you mean GX470 or the '10 - '13's?
My guess unless you had a 2022 or newer and it didn't work on that, then maybe, and that's a big maybe, it'll work on older GX's.
But I don't think there's really any difference behind the dash between your 2018 and my '13.

Maybe not. I just know some electronic items on the GX460 changed multiple times through the years (parking sensors are one example), so maybe something changed in the speedometer function too. But it is just speculation, I could easily be wrong.

In any case I would really be interested to hear of any other experiences with this unit in a GX460, because I am left wondering if this is a systemic problem with the GX460 or a problem with the individual unit I had. Surely somebody else has tried it?

 

[BigSwede]

Does anybody know where the GX derives its speedo data from?

I got to thinking about this during the long drive to Utah, and it occurs to me that the speedo should actually be reading high with 4.88s and 35s, rather than low... that is IF the GX used an old school speedo drive from the transmission. Instead, the speedo is reading 10% low, which means the GX is getting speedo data from something like a wheel speed sensor.

 

[Washingtontaco]

Does anybody know where the GX derives its speedo data from?

I got to thinking about this during the long drive to Utah, and it occurs to me that the speedo should actually be reading high with 4.88s and 35s, rather than low... that is IF the GX used an old school speedo drive from the transmission. Instead, the speedo is reading 10% low, which means the GX is getting speedo data from something like a wheel speed sensor.

Unsure where the GX gets its signal? That being said when I regeared I had to adjust my Scan Gauge a few %. The speedo still reads low. IDK why? 285/75/17 or 34"tires and 4:88 gears, it should be reading a bit fast?

 

[BigSwede]

Unsure where the GX gets its signal? That being said when I regeared I had to adjust my Scan Gauge a few %. The speedo still reads low. IDK why? 285/75/17 or 34"tires and 4:88 gears, it should be reading a bit fast?

It definitely *should* be reading fast. The fact that it isn't suggests a data source somewhere other than the drivetrain.

 

[Acrad]

 

[BigSwede]

Thanks Acrad... and I assume the skid control ECU gets its information from the wheel speed sensors, as I thought. Interesting... not sure what I can do with that information with regard to speedometer correction, but good to know.

 

[ericm979]

Unsure where the GX gets its signal? That being said when I regeared I had to adjust my Scan Gauge a few %. The speedo still reads low. IDK why? 285/75/17 or 34"tires and 4:88 gears, it should be reading a bit fast?

Adjusting it on the Scan Gauge just affects the ScanGauge. Speed readout, mileage, etc.

 

[Washingtontaco]

View attachment 3314082View attachment 3314083View attachment 3314084

There's your sign!

 

[Washingtontaco]

Adjusting it on the Scan Gauge just affects the ScanGauge. Speed readout, mileage, etc.

Yes, I know this....