Scangauge II

[mikepeters1983]

Hey I was just wondering if there was any other way to change the speedo on the trailblazers? would a Scangauge II work? if not what else is out there besides PCMFORLESS tune?

[janesy86]

Scangauge doesn't change the speedo on the dash, but will display a corrected speedo itself once you change the speedo option on the Scangauge to match the tire change percentage.

And I have the PCMforless tune but it did not fix my speedo.

[Zero]

Scangauge doesn't change the speedo on the dash, but will display a corrected speedo itself once you change the speedo option on the Scangauge to match the tire change percentage.

And I have the PCMforless tune but it did not fix my speedo.

Well said, and totally correct. Same thing for me with my truck. Love my scangauge.

[mikepeters1983]

So what I am getting is that I should just get the scangage right now and get the tune later?

[Gordinho80]

My opinion... my Scanguage did more for my fuel economy when I first got it then the tune did. It could be all in my head. I think I noticed a tiny bit more pick up with the tune over stock, I think... I have the SG displaying MPG and Average MPG... for the first few weeks, I tried to max out both numbers while still maintaining my travel time. Now, I barely pay attention and my mileage has been crap again... LOL

[mikepeters1983]

So then its settled then I will be getting the scanegauge at the end of this week

[janesy86]

I'd say both are great. Maybe scangauge first so you can keep an eye on the trans temp and have corrected speedo dislayed.

But I did notice quite a significant boost in the performance from the tune, mostly that it has instant throttle response as opposed to the slight delay of power once stepping on the gas before the tune.

But I'll def reccomend both.

[mikepeters1983]

well yea I am getting both, but just wanted to know what I should get first.

[high-voltage]

A tune from PCMforless will make your speedo correct if you tell them the stock tire size and the currant tire size.

[The Roadie]

PCMforless failed to correct my speedo in two attempts. Been reported a few times on the OS - there's some extremely hidden parameter they don't have the software tool or precise knowledge to adjust, after finding and correcting at least two other places. Frustrating, but it's the only item of their tunes I was never satisfied with.

[mikepeters1983]

so let me ask this then lol, first the scanguge then tune? that a smart way to go?

[janesy86]

A tune from PCMforless will make your speedo correct if you tell them the stock tire size and the currant tire size.

Yep didn't work for me. Many of us here have reported this. Maybe it worked for you?

[mikepeters1983]

Thank you everyone I love this site lol, saved me from poss getting the wrong thing first

[fishsticks]

My speed is closer now than it was before my tune. I told them to adjust for my gears and 33" tires. There's definitely a change and I suspect once I go to 33's it will be on target.

Did folks get their PCM tuned or get the core package? I got the core so I'd have a spare. Maybe it's easier to correct in the older models?

[DJones]

I got the tune first, but they forgot to remove P1481. They said when I send it back, they will fix it and reimburse me for shipping. I think it is contributing to my (what seems to be) really poor mileage.

As for the speedo correction, I think if anything I'll stick with stock tires sizes, for now. (17's have almost the same OD as the 16's (online calculator))

[Trail X]

... I suspect once I go to 33's it will be on target.

Is your speedometer over-estimating as of now? If not, it will only get farther off target.

[Saxis]

The question is: Are you having your PCM tuned for NOMINAL size or ACTUAL size? Looking at most tire specs and especially off-road tires, actual sizes are usually +/- .5" at least from their nominal size. It seems that could be 1-2 mph difference right there.

[fishsticks]

... I suspect once I go to 33's it will be on target.

Is your speedometer over-estimating as of now? If not, it will only get farther off target.

Yes, my speedo is reading faster than my GPS currently. It has been since I regeared. But it's closer than it was now... so there was a definite change.

[high-voltage]

A tune from PCMforless will make your speedo correct if you tell them the stock tire size and the currant tire size.

Yep didn't work for me. Many of us here have reported this. Maybe it worked for you?

Yea I worked for me.
I didn't send my PCM in or get a core. I had someone with EFI live load the tune for me.

[djthumper]

Yeah that would be nice to have that equipment. Maybe after I get most of it built I will look into getting EFI live or get lucky and run across someone that has one near by.