The point is that you have to lie to the system or the system will shut you down
due to "incorrect gear ratio". Using the tone rings is one way of doing it.

 

A GPS based speedometer might not update fast enough to be practical.

Directly driving the stepper motor on the speedometer is much more effective,
and does not affect the instrument pack once you sever the stepper motor
drive. This can be done with a $40 computer no bigger than a deck of cards.

As a matter of fact, that same $40 computer has enough power and peripherals
to manage both the speedometer drive and ABS translation. It's just more
complex than using the FRP black box.

This won't get around recording higher accumulated mileage though as that
is recorded and maintained by the instrument pack.

 

The TCM gets the speed over CAN so rather than messing with the input to all the vehicle systems why not spoof that one signal to the TCM?

You would have to intercept all the CAN traffic and rebroadcast it to the TCM unchanged except for substituting the fake speed.

I have been exploring a method like this as a way to have a paddle shifter like the newer cars. The linear switch module is a CAN node that broadcasts a few messages to tell the TCM to be in 5,4,3,2.

TCM is more complicated because there are more messages and the TCM both sends and receives data, but the principle should apply.

 

Me too!

Its still unclear to me, where does one obtain a compatible direct replacement differential (requiring minimal mods), with steeper gearing, that bolts up to a 2004? Sorry if I overlooked this, but it seems like I've only seen this info in relation to '02 and previous.

Regarding reflashing, THIS THREAD looks promising (SDD crack), but does it resolve the speedo issue?

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