Hey guys. Not sure of the best place to post but wanted to let everyone know that I was able to apply a speedometer correction to my 2009 Outback XT. I know that its not a huge deal but I believe that this can be applied over multiple applications like most can-bus, abs and vdc equipped vehicles including STi for those that are interested.
The reason that I mention it here is because when I searched before the results I found (and instructions from manufacturers) said that this was not possible due to the proprietary can-bus protocol.
I hope this helps...
I used the Healtech SH-V4
https://www.healtech-electronics.com/products/sh/
A little background, I have an automatic which has 6 speed sensors. I believe the manual trans is only 4 speed sensors. None of this will matter with this method. Our speedometers are driven by stepper motors which means digital signal (similar to a wheel speed signal).
The wheel speed sensor is typically fed into the transmission computer, then processed and sent to the vdc(if equipped) and/or the abs computer. In my case the vdc and abs signal wires are merged and this signal is fed to the speedometer where an additional processor converts for use with the speedometer.
Rather than intercept the wheel speed sensor wire before the computers for all 4/6 sensors with the Healtech or convertor I intercepted the signal just upstream of the speedometer processor with one converter. (Plug B34 Pin 21 Green with Black Stripe). My plug was vertical just below the glove box. (I'll add pics later)
This is similar intent to using the healtech convertor on a motorcycle.
WI-177.pdf
WI208.pdf
WI209.pdf
WI-211.pdf