Pounder

Can someone tell me how to reprogram the speedo with a knockoff Tech 2 ???? I can't seem to find out how ???

dadaroo

The Tech 2 was not designed to do that. GM wanted to limit the technicians to only program GM approved changes to the PCM and BCM.

Pounder

No guys, I'm talking about the speedometer, I changed the tires on the car. fronts are 245/40/18 and the rear are 295/35/19 . the speedometer at 70 is really 72 by my GPS !!!!

dadaroo

There is an entry for Speed Cal. Reprogramming but I can't say it will do what you want.

I can try and see what I find out with my car when I get a chance.

Pounder

Thanks !!!!

lionelhutz

If it's always off by 2mph then there is no real fix. Calibrating it at one speed would make it out at all other speeds. But, if it's really off by 3% then you could calibrate it.

My speedometer always reads a fixed amount above the DIC cruise setting display (Which is correct) or a GPS reads so there is no fix for it. It's about about the opposite of yours, maybe 2mph on the high side.

Pounder

No it's incremental at 35 it's close !!!!!!!!!!!!

jcgunn

Some of the hand held tuners can adjust for different tire sizes, that might do the trick.

Pounder

Tried with a Superchips no go !!!!!!!!!!!!!

Vetteman Jack

Let us know if you get it figured out and what worked.