Inaccurate analog speedometer

[JudgeM]

Hi all.

I think many of you know that the speedometer readings in some Yaris are not accurate. I suspected this and confirmed with GPS.
I found that a speedo reading of 100kmh had actual speed of 90kmh.

I was playing around with Techstream and I ran the instrument cluster diagnostic. I found that the speedometer was infact inaccurate and even the tachometer !.

Please see these videos I made. In the second video I test the digital meter which IS accurate.

Techstream speedometer test on analog meter:
https://www.youtube.com/watch?v=5LLENLt-is4

Techstream speedometer test on digital meter:
https://www.youtube.com/watch?v=yFrP4yERDzY

I think its quite interesting. :rolleyes:
Anyone else tried this out ?
Is there anyway to 'calibrate' the speedometer?

[CTScott]

The only way I have found to calibrate them is to digitally modify the signal between the transmission and the cluster. I have only had to calibrate due to tire size differences (and only correctly 2-3 MPH at 60 MPH).

I have never seen one that far off though. I would almost suspect that the stepper motors that drives the needles are damaged from someone removing and re-installing the needle with too much force.

[Astroman]

This was posted in the wrong section, moved it. Please remember to post your threads in the correct section. :thumbsup: