Crank Relearn.......P1336.......how to do it
I'll keep this alive. Do I need to do a case relearn since I replaced my PCM? The car will not REV past 4000 RPM in park or neutral.
The car also sounds like it has a misfire. Could it be because of this? It never used to do that with the old PCM.
It does not take my VE changes after I flash them in the PCM.
Please help me out with this, since I have hit a brick wall.
The car also sounds like it has a misfire. Could it be because of this? It never used to do that with the old PCM.
It does not take my VE changes after I flash them in the PCM.
Please help me out with this, since I have hit a brick wall.
Staging Lane
Joined: Jun 2011
Posts: 66
Likes: 0
From: Nebraska
Crank Relearn Using the Tech II go in to diagnostics and then go to module setup and then it tells you step by step how to do it make sure you have a rev limiter on.. This might work not sure if its cammed thought
I'll keep this alive. Do I need to do a case relearn since I replaced my PCM? The car will not REV past 4000 RPM in park or neutral.
The car also sounds like it has a misfire. Could it be because of this? It never used to do that with the old PCM.
It does not take my VE changes after I flash them in the PCM.
Please help me out with this, since I have hit a brick wall.
The car also sounds like it has a misfire. Could it be because of this? It never used to do that with the old PCM.
It does not take my VE changes after I flash them in the PCM.
Please help me out with this, since I have hit a brick wall.
Once again guys and gals, IT'S FOR MISFIRE PURPOSES ONLY! Once you modify an engine, specifically an aftermarket cam, you disturb what was a SMOOTH ROTATION of the crankshaft. The case relearn is there so the computer can "learn" the small idiosyncrasies in crank to cam timing. It uses this information to better detect small misfires. There is no credible evidence it's used for anything more.
Not only that, but through tuning, you dumb down the misfire detection by altering the misfire tables. This is a must, otherwise the computer will repeatedly throw misfire codes as it's detecting the uneven rotation of the crank, caused by the lopey cam.
Additionally, turning off the code in the computer does nothing but keep it from setting the P1336. With the code turned off, it can still detect misfires. The ONLY TIME IT CANNOT DETECT MISFIRES IS WHEN THE CODE IS SET!
As a side note, the ONLY scan tool I've had repeated success using to run the case relearn, is a TECH2. All of the aftermarket scanners seem to have some problems. Not saying they won't or can't do it, but I've had mixed results with most all of them. Keep in mind I own 5 different scanners, besides my HPT or EFIlive.
So I need to know. Do I need to do anything with this? I am throwing the p1336 code. Should I have my tuner get risk of it. Or should I do something else? I can post my .hpt file if need. Thanks.
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TECH Senior Member
Joined: Apr 2002
Posts: 6,080
Likes: 17
From: So.Cal.
I'll keep this alive. Do I need to do a case relearn since I replaced my PCM? The car will not REV past 4000 RPM in park or neutral.
The car also sounds like it has a misfire. Could it be because of this? It never used to do that with the old PCM.
It does not take my VE changes after I flash them in the PCM.
Please help me out with this, since I have hit a brick wall.
The car also sounds like it has a misfire. Could it be because of this? It never used to do that with the old PCM.
It does not take my VE changes after I flash them in the PCM.
Please help me out with this, since I have hit a brick wall.
- P/N rev limiter is set to 4000,
- you have a misfire problem (due to: ignition, lean/rich, air leak, compression leak, other);
How do you know the PCM doesn't flash...? When you read it back does it compare the same...? If MAF is being used, then VE table is used only during throttle/airflow transients, so you won't see the changes unless you disable the MAF and LTFT/STFT trimming.
Or you may have a PCM with a problem.
This is an SD car. So there is no MAF. If it is the PCM this would be my 2nd one. I will be able to do a few test to the car in the next day or two to see what really might be going on. If anything changes I will post here.
The rev limiter is set only if its in neutral or park. But isn't that how it just is from the factory? The trans is a 4l80e with FMVB. The PCM flashes but all the changes I make to the VE tables stay the same. I will double check or I can post my .hpt file so you guys can look over it.
The rev limiter is set only if its in neutral or park. But isn't that how it just is from the factory? The trans is a 4l80e with FMVB. The PCM flashes but all the changes I make to the VE tables stay the same. I will double check or I can post my .hpt file so you guys can look over it.
You guys wanna hear some funny ****.................I've had some weird missing/stumbling issues in the past week or so....my Crank Relearn code has been on for more than a year because my relearn would not PASS no matter how many times we tried it. So I said screw it and left it on, it had no effect on how my engine performed.
Since these weird missing/stumbling issues have started....that code is gone and does not show up anymore.
WTF!!!!!!
These PCM's are just wacky, silly little bastards.
.
Since these weird missing/stumbling issues have started....that code is gone and does not show up anymore.
WTF!!!!!!
These PCM's are just wacky, silly little bastards..
TECH Senior Member
Joined: Apr 2002
Posts: 6,080
Likes: 17
From: So.Cal.
This is an SD car. So there is no MAF. If it is the PCM this would be my 2nd one. I will be able to do a few test to the car in the next day or two to see what really might be going on. If anything changes I will post here.
The rev limiter is set only if its in neutral or park. But isn't that how it just is from the factory? The trans is a 4l80e with FMVB. The PCM flashes but all the changes I make to the VE tables stay the same. I will double check or I can post my .hpt file so you guys can look over it.
The rev limiter is set only if its in neutral or park. But isn't that how it just is from the factory? The trans is a 4l80e with FMVB. The PCM flashes but all the changes I make to the VE tables stay the same. I will double check or I can post my .hpt file so you guys can look over it.
TECH Senior Member
Joined: Apr 2002
Posts: 6,080
Likes: 17
From: So.Cal.
Staging Lane
Joined: Feb 2007
Posts: 70
Likes: 0
You can say it til you're blue in the face, for whatever reason, people don't seem to get it.
Once again guys and gals, IT'S FOR MISFIRE PURPOSES ONLY! Once you modify an engine, specifically an aftermarket cam, you disturb what was a SMOOTH ROTATION of the crankshaft. The case relearn is there so the computer can "learn" the small idiosyncrasies in crank to cam timing. It uses this information to better detect small misfires. There is no credible evidence it's used for anything more.
Not only that, but through tuning, you dumb down the misfire detection by altering the misfire tables. This is a must, otherwise the computer will repeatedly throw misfire codes as it's detecting the uneven rotation of the crank, caused by the lopey cam.
Additionally, turning off the code in the computer does nothing but keep it from setting the P1336. With the code turned off, it can still detect misfires. The ONLY TIME IT CANNOT DETECT MISFIRES IS WHEN THE CODE IS SET!
As a side note, the ONLY scan tool I've had repeated success using to run the case relearn, is a TECH2. All of the aftermarket scanners seem to have some problems. Not saying they won't or can't do it, but I've had mixed results with most all of them. Keep in mind I own 5 different scanners, besides my HPT or EFIlive.
Once again guys and gals, IT'S FOR MISFIRE PURPOSES ONLY! Once you modify an engine, specifically an aftermarket cam, you disturb what was a SMOOTH ROTATION of the crankshaft. The case relearn is there so the computer can "learn" the small idiosyncrasies in crank to cam timing. It uses this information to better detect small misfires. There is no credible evidence it's used for anything more.
Not only that, but through tuning, you dumb down the misfire detection by altering the misfire tables. This is a must, otherwise the computer will repeatedly throw misfire codes as it's detecting the uneven rotation of the crank, caused by the lopey cam.
Additionally, turning off the code in the computer does nothing but keep it from setting the P1336. With the code turned off, it can still detect misfires. The ONLY TIME IT CANNOT DETECT MISFIRES IS WHEN THE CODE IS SET!
As a side note, the ONLY scan tool I've had repeated success using to run the case relearn, is a TECH2. All of the aftermarket scanners seem to have some problems. Not saying they won't or can't do it, but I've had mixed results with most all of them. Keep in mind I own 5 different scanners, besides my HPT or EFIlive.
That the CASE relearn does not affect how the engine runs and is purely for diagnostics?
Moderator
Joined: Aug 2010
Posts: 7,323
Likes: 529
From: Ann Arbor, MI
EDIT: A more experienced tuner disagrees - see below.
I'm not an expert, but my personal single experience is different from edcmat-l1.
After I replaced the stock balancer on my LS2 with an ATI, I got camshaft sensor code (IIRC P0341) which would quickly come back after clearing it.
Thinking I must have damaged it during the balancer change, I bought and installed a new one, but still got codes. I then performed the crank relearn and the code never came back.
I'm not an expert, but my personal single experience is different from edcmat-l1.
After I replaced the stock balancer on my LS2 with an ATI, I got camshaft sensor code (IIRC P0341) which would quickly come back after clearing it.
Thinking I must have damaged it during the balancer change, I bought and installed a new one, but still got codes. I then performed the crank relearn and the code never came back.
Last edited by mrvedit; Apr 16, 2015 at 04:29 PM.
Moderator
Joined: Aug 2010
Posts: 7,323
Likes: 529
From: Ann Arbor, MI
Moderator
Joined: Aug 2010
Posts: 7,323
Likes: 529
From: Ann Arbor, MI
Also then, what symptoms indicate that a CASE Relearn is needed?
I found this informative thread on when various types of GM "Relearns" are needed and how to perform them:
http://www.fullsizechevy.com/forum/g...t-relearn.html
I found this informative thread on when various types of GM "Relearns" are needed and how to perform them:
http://www.fullsizechevy.com/forum/g...t-relearn.html
Also then, what symptoms indicate that a CASE Relearn is needed?
I found this informative thread on when various types of GM "Relearns" are needed and how to perform them:
http://www.fullsizechevy.com/forum/g...t-relearn.html
I found this informative thread on when various types of GM "Relearns" are needed and how to perform them:
http://www.fullsizechevy.com/forum/g...t-relearn.html