RGMEPP

We got the old P1336. Guess it needs a relearn. Surprised that it runs so well with code. Safe to for now ????? Anybody in the St. Louis area got a good name for the relearn ???? Would like to avoid the "STEALERSHIP" for sure.

gmtechnician

anyone with a quality scan tool can do it. its pretty hard to mess up.

TG02Z71

iTrader: (2)

The relearn doesn't relly mean **** from my experience. I've been through at least seven revisions of my Nelson tune and drove months with the SES light on for the crankshaft re-learn. I noticed no better performance after the re-learn was done. Just my personal findings.
The light bugs you at first, then it does not seem to matter once your used to changing you tune as you do upgrades.

MorepowerTY

Does this happen after all the nelson or anyone tunes? I'm going to get a nelson tune, but don't need the aggervation of that. Or is it just once and while?

TXsilverado

iTrader: (19)

its just every once n a while. most people get away without needing a crank relearn.

Colby 04

It can happen from anybody's tunes. I had the crank relearn code with my W4M tune, but not my Nelson tune. W4M didn't enable my electric fans and Nelson didn't disable my rear O2's - so glitches are just a fact of life with tuners IMO.

erronisme

from what I understand the crank position sensor, cam position sensor and the computer are no longer syncronized together, so the computer has more or less lost the signal.
As a back up or going to limp mode the computer just uses the cam position sensor to set the timing instead of both. Its not as accurate, but its close enough.

Thats just the way I had understood it. And its not that big of a deal.

TG02Z71

iTrader: (2)

It had been stated here numerous times that if you had your stock PCM tuned and did not replace it with another, then you wouldn't have to do the re-learn.
I don't really know if that is true though. My truck has not had the stock PCM in for about 1.5 years now.

hog

if you get your stock PCM tuned and reinstall it into your truck you wont get a SES light so the CASE relearn wont be needed.

Every single PCM equipped vehicle that rolls off the assembly line has a crank (CASE) relearn performed. If the dealership has to install a new PCM in your truck, they do a relearn. The same goes for crankshaft, crank position sensor, or shortblock or full engine replacement.

A CASE (crank) relearn simply accustomes the PCM to the EXACT position of the crankshaft and camshaft.

If you dont get a relearn performed, your truck cannot detect missfires.

The relearn has NOTHING to do with power at all, I want to know if my truck is experiencing missfires. I also like to know EXACTLY when another problem occurs, not when I happen to run an OBD2 scan.

peace
Hog

RGMEPP

Did some further research on this, and heard from Allen. Perfectly safe to drive, can happen anytime you get a tune, doesn't happen often, except for the '99 - '02's. I'm an '01, and fall into that group that gets it alot.
Whatever you do, don't let this make you worry about a "Nelson" tune. Can happen with any tune, and this big pig of a truck now screams like a banshee !! Seeing as how mine gets used as a "truck" most of the time, I am cammed small, for low - mid torque. The increase he got me there is great. Cam not meant to go beyond 5000 RPM's, but it pulls hard to 5800. from a dead stop, it smokes 'em through 1st & 2nd. At 20 MPH, it breaks loose as it d'shifts to 1st & chips 'em at 2nd. Truck just runs better overall. Allen is Da Man !!
Will add a smokey one to the photo bucket later, and reply to let all know its there if interested.