speedo calibration

[mr. monte]

Does anyone know if there's a programmer that will recalibrate the speedometer with out leaving a "footprint" in the computer :confused:

[Kennedy]

I really don't think so, but at the dealer level there is no way to detect. My best advice is to swap to a core ECM and do your playing on it while keeping the stock unit stock.

[mr. monte]

if I get that core, it's coming to you Mr. Kennedy ;)

I wanted to be able to switch back to the stock tires when needed

[Kennedy]

Just to elaborate a bit:

It's been said by trusted source that many of these hand held programmers leave stuff behind. Some are worse than others and I'd about guarantee that the Tri-Buy ones and most anything on the same platform do. Now a Tech at the dealership will not likely know how to check this, but GM surely can. The other likely way to tell is the date that it was last written to.

I had a situation where a LMM owner came to me with a limped truck due to a plugged DPF. He'd been running one of the popular 3 letter tuners that is supposedly DPF safe. He claims that he returned the truck to stock and took it to the dealer. The dealer diagnosed and had to call GM to get approval. GM had the Tech look up some numbers on the Tech 2 and report back. When he gave the numbers the Techline stated that they were not to proceed until the ECM was replaced as the aftermarket tunes are never truly out of the ECM. The biggest problem in all of this is that he was blind sided as the owner said the truck was bone stock. I'm not sure how much of this I buy, but I have spoken with the Tech and he and I share a mutual respect for one another.

In the end the guy left here with a LLY exhaust;) a new stock ECM, and a custom tune on his original with the idea that he should put the ECM in and have the dealer proceed with fixing the truck. He did not return to the dealer as the truck runs great now.

[mr. monte]

I'll wait to get another ECM. If I do pick-up these 285's, I'll just use my GPS for a speedometer for now

[linchhummmer]

why dont you just ues the programer i just had my truck in the shop and they didnt say anything it and they put in a new injector with the warrante

[mr. monte]

GM has gotten real touchy about tire diameter with the six speed, they won't even give me a maximum tire diameter allowed under the warranty, just say a 265/75R16 is a acceptable replacement "IF" you take it in to the dealer to have it re calibrated :rolleyes:

[linchhummmer]

they said the same thing about the lb7 when they came out but ive never heard anyone having a warentee dropped do to iti have them on my truck and i have never heard anything about it, like i said last week i had my truck in the shop with edge and ats and fass all in the truck and they didnt say anything but i have heard they are getting hard on the lmm's

[mr. monte]

not really worth the risk of voiding my 100,000 warranty when there's only 15,000 on it. One warranty trip to the stealer would pay for most of the "toys" I want to put on it

I've heard what a set of those injectors cost :eek:

[NutNbutGMC]

GM has gotten real touchy about tire diameter with the six speed, they won't even give me a maximum tire diameter allowed under the warranty, just say a 265/75R16 is a acceptable replacement "IF" you take it in to the dealer to have it re calibrated :rolleyes:
I run 265s and my speedo hasn't changed. I have checked the mile markes on the interstate at 1/10, 1 mile and extended miles. The markers are much closer than any GPS.

In addition, I have paced the speed with other automobiles..still dead on.

All of the road-side radar speed reminders are dead on as to what the speedo says. I don't think I'd worry two hoots about 245a VS 265s VS 285s and the need for a calibration. The 285s may make a slight difference (mathmatically in diameter and distance), but it's not like you're running a nano-second road race.

Don't take my word for it. Check for yourself.

Radar, mile marker, and pacing... doesn't get much more confident than that.